Short answer
The Prophet Muhammad (ﷺ) was gentle, humble and forgiving, and he taught that good character is the heart of faith. His wife Aisha said his character was the Qur'an: he lived what he taught. She said he never struck a woman or a servant, and never took revenge for his own sake. Anas served him for ten years and was never once scolded. Though he led a state, he helped with the housework and carried earth beside his men. He visited the sick, even a Jewish boy who had served him. When a chief of Ta'if turned him away, an angel offered to destroy the people who had rejected him. He refused and hoped that their children would worship God (﷾). A good word is charity, he said, and God (﷾) looks at hearts, not faces. The Qur'an calls him a beautiful pattern for believers.
Full explanation
What the Qur'an says of him
The Qur'an tells the Prophet (ﷺ) that he stands on an exalted standard of character. It says his gentleness was a mercy from God (﷾), and that people would have left him had he been harsh. It calls him a beautiful pattern for anyone who hopes in God (﷾), and a mercy to all creatures.
“And thou (standest) on an exalted standard of character.”
“It is part of the Mercy of Allah that thou dost deal gently with them Wert thou severe or harsh-hearted, they would have broken away from about thee: so pass over (Their faults), and ask for (Allah's) forgiveness for them; and consult them in affairs (of moment). Then, when thou hast Taken a decision put thy trust in Allah. For Allah loves those who put their trust (in Him).”
“Ye have indeed in the Messenger of Allah a beautiful pattern (of conduct) for any one whose hope is in Allah and the Final Day, and who engages much in the Praise of Allah.”
“We sent thee not, but as a Mercy for all creatures.”
Those who lived with him
The people who saw the Prophet (ﷺ) at home tell the same story. His wife Aisha said his character was the Qur'an. She said he never struck a woman or a servant, and never took revenge for his own sake. Anas, who served him from boyhood, said that in ten years he was never once spoken to with impatience.
Sa'd ibn Hisham asked Aisha about the character of the Prophet (ﷺ). She asked him whether he did not read the Qur'an, and said that the character of the Prophet was the Qur'an.
Aisha reports that the Prophet (ﷺ) never struck anyone with his hand, neither a woman nor a servant, except when fighting in the cause of Allah. He never took revenge for anything done to him, unless something Allah had made sacred was violated; then he acted for Allah's sake.
Aisha reports that whenever the Prophet (ﷺ) was given a choice between two things he chose the easier, unless it was sinful. He never took revenge for his own sake, only when the limits Allah set were violated.
Anas reports that he served the Prophet (ﷺ) for ten years, and the Prophet never once said even a word of impatience to him, nor asked him why he had done something or why he had not.
Humble in power
The Prophet (ﷺ) served his family at home. He carried earth with his companions when they dug the trench around Medina. He visited a Jewish boy who had served him when the boy fell ill. Umar, a leading companion, once found him on a bare mat of palm leaves, its marks pressed into his side. Umar wept, because Caesar and Khosrau (the rulers of Rome and Persia) lived in luxury. The Prophet (ﷺ) answered that they could have this world. He died with his armour pawned for barley. He would not even let his followers stand before him the way the Persians and Romans stood before their kings. He told them not to over-praise him as the Christians over-praised the son of Mary. He was only a servant, so they should call him the servant of Allah (﷾) and His Messenger.
Al-Aswad asked Aisha what the Prophet (ﷺ) used to do at home. She said he busied himself serving his family, and when the time for prayer came he went out to pray.
Al-Bara reports that on the day of the Confederates he saw the Prophet (ﷺ) carrying earth, the dust covering his belly, as the trench was dug.
Anas reports that a Jewish boy who used to serve the Prophet (ﷺ) fell ill, and the Prophet went to visit him. He sat by his head and invited him to Islam; the boy looked at his father, who told him to obey, and he accepted.
Umar found the Prophet (ﷺ) lying on a mat of palm leaves with nothing between him and it, a leather pillow stuffed with palm fibre under his head. Seeing the marks of the mat on his side, Umar wept, saying that Caesar and Khosrau lived in luxury while he lived in want. The Prophet asked whether he was not content that they should have this world and the believers the Hereafter.
Aisha reports that when the Prophet (ﷺ) died, his armour was held by a Jewish man as security for thirty measures of barley.
Jabir reports that the Prophet (ﷺ), when ill, led the prayer sitting, and the people behind him stood. He signalled them to sit, and afterwards told them they had nearly done what the Persians and Romans do, who stand before their kings while the kings sit, and that they must not do it.
Umar reports that he heard the Prophet (ﷺ) say: do not over-praise me as the Christians over-praised the son of Mary; I am only a servant, so call me the servant of Allah and His Messenger.
Mercy to those who wronged him
The Prophet (ﷺ) was asked if any day had been harder than Uhud (a battle near Medina). He said the worst his own people ever did to him came on the day a chief of Ta'if turned him away. Ta'if is a town near Mecca. He left in deep sorrow. An angel offered to bring the two mountains of Mecca down on his people, who had rejected him. He refused, and said he hoped their children would worship God (﷾) alone. Once a bedouin (a desert Arab) dragged him by his cloak so hard it marked his shoulder and demanded money. The Prophet (ﷺ) smiled and ordered him a gift.
Aisha asked the Prophet (ﷺ) whether he had known a day harder than Uhud. He named the day he presented his call to Ibn Abd Yalil, a chief of Ta'if, and was turned away. As he left in sorrow, Gabriel came with the Angel of the Mountains, who offered to let the two great mountains fall on those who had rejected him. The Prophet refused and said he hoped that their descendants would worship Allah alone.
Anas reports that a bedouin pulled the Prophet's (ﷺ) cloak so roughly that its hem left a mark on his shoulder, and demanded to be given some of the wealth Allah had given him. The Prophet turned to him, smiled, and ordered that he be given a gift.
What he taught
The Prophet (ﷺ) taught that the best people are the best in character, and that believers are one body. No one truly believes until he wants for his brother what he wants for himself. Whoever is not merciful to others will not be shown mercy. No kindness is small, not even a cheerful face, and a good word is charity. A believer is good to his neighbour. God (﷾) looks at hearts and deeds, not faces and wealth. A worker is paid before his sweat dries. A man was forgiven for giving water to a thirsty dog.
Abdullah ibn Amr reports that the Prophet (ﷺ) was never coarse or foul in speech, and used to say that the best of people are those with the best character.
Nu'man ibn Bashir reports that the Prophet (ﷺ) said the believers, in their love, mercy and kindness to one another, are like one body: when one part aches, the whole body shares its sleeplessness and fever.
Anas reports that the Prophet (ﷺ) said none of you has faith until he wishes for his brother what he wishes for himself.
Jarir ibn Abdullah reports that the Prophet (ﷺ) said that whoever is not merciful to others will not be treated with mercy.
Abu Dharr reports that the Prophet (ﷺ) told him not to think any good deed small, even meeting his brother with a cheerful face.
Abu Huraira reports that the Prophet (ﷺ) said charity is due for every joint of the body each day: judging fairly between two people is charity, helping a man onto his mount or lifting his baggage is charity, a good word is charity, every step to prayer is charity, and removing something harmful from the road is charity.
Abu Huraira reports that the Prophet (ﷺ) said whoever believes in Allah and the Last Day should speak good or keep silent, should be kind to his neighbour, and should honour his guest.
Abu Huraira reports that the Prophet (ﷺ) said: Allah does not look at your faces or your wealth, but He looks at your hearts and your deeds.
Abdullah ibn Umar reports that the Prophet (ﷺ) said: give the worker his wage before his sweat dries.
Abu Huraira reports that the Prophet (ﷺ) told of a thirsty man who drank from a well, then saw a dog licking mud from thirst. He climbed down again, filled his shoe with water and gave the dog a drink, and God thanked him and forgave him. Asked whether there is reward for kindness to animals, the Prophet said there is reward for kindness to every living thing.
Did he ever hit Aisha?
Sahih Muslim 974 — Kitab al-Jana'iz (The Book of Funerals), hadith 974
Aisha reports that one night the Prophet (ﷺ) slipped out quietly, and she followed him to the graveyard of al-Baqi', where he prayed for the dead. She ran home ahead of him, and when he found her out of breath and learned what she had done, he gave her a push on the chest that hurt her, and asked whether she thought that God and His Messenger would treat her unjustly. He then told her that Gabriel had called him out to pray for the people of al-Baqi'.
Cited for
Aisha herself says he struck her chest and it hurt, so he did strike a woman.
The response
Aisha's word is lahada, a push on the chest. It hurt, and she says so. But it was a single push while he was speaking to her, not a blow. Aisha herself tells both reports: this push, and that he never struck a woman or a servant with his hand.
Where it lands — One push on the chest, told by Aisha herself, is not the blow of the hand she says he never gave a woman.
Perspectives
The Islamic perspective
The Prophet Muhammad (ﷺ) is the model of conduct God (﷾) set for believers. Those closest to him describe a man who was gentle at home, humble in power and forgiving to his enemies. His sayings make good character the measure of faith.
The Qur'an says the Prophet (ﷺ) stands on an exalted standard of character and is a beautiful pattern for believers.
Aisha described his character as the Qur'an itself.
He never struck a woman or a servant, and never took revenge for his own sake. He acted only when God's (﷾) limits were violated.
Anas served him for ten years without once being spoken to in impatience.
He served his family at home, carried earth at the trench and visited a sick Jewish servant boy.
He refused the honours of a king and warned against exaggerated praise of himself.
He was offered the destruction of the people of Mecca who had rejected him. Instead he hoped that their children would worship God (﷾) alone.
He taught that the best people are those with the best character.
He taught that God (﷾) looks at hearts and deeds, not at faces and wealth.
He taught that there is reward for kindness to every living creature.