1) Once a person asked him to invoke cure, he said: I have not been sent to curse, but I have been sent as a mercy unto the worlds. Once he was returning from the battle. He passed by a plain. The sun was hot and the people were resting under the shades of the trees. The Holy Prophet (peace and blessings of Allah be upon him) went to sleep under the shade of a tree hanging his sword to a branch. A bedouin came there and took off his sword intending to kill him (the Holy Prophet). The Holy Prophet (peace and blessings of Allah be upon him) was startled to see a bedouin standing on the side of his head with an unsheathed sword in his hand. He (the bedouin) said: Tell me, who can save you now from me? He said: (It is) Allah. This impressive reply had its effect and he put the sword back into its sheath.
2) He forgave Hinda, the wife of Abu Sufyan who tore out the heart and liver of his (the Holy Prophet's) loving uncle.
3) He forgave Habbar b. Al. Aswar who had inflicted severe injury to the Prophet's loving daughter Zainab (May Allah be pleased with her).
4) During the Treaty of Hudaibya, a band of sixty men descended the mount of Tanim at dawn, with an intention to kill he Prophet (peace and blessings of Allah be upon him). They were arrested; but the Holy Prophet (peace and blessings of Allah be upon him) let them off.
5) A person intended to kill him. The companions of the Holy Prophet (peace and blessings of Allah be upon him) caught hold of him and brought him to the Holy Prophet (peace and blessings of Allah be upon him). He trembled out of fear. The Holy Prophet (peace and blessings of Allah be upon him) said to him : Do not be afraid, even if you intended to kill me, you could not do so.
6) The people of Ta'if hooted him through the streets listening to the call of Islam and refused to give him shelter. They pelted him with stones and blood flowed down upon his legs. The angel said to him: If he desired we cause the mountain to fall upon them. He said: No, perhaps any believer of Allah may be born from their progeny.
The Source is given here
http://www.answering-christianity.com/umar/meccan10_rebuttal.htmwhich is,
(Source: Sirat-Un-Nabi, Vol.5 by Syed Sulaimain Nadwi, rendered into English by Mohd. Saeed Siddiqi, Kitab Bhavan New Delhi, p.229-230)
but i need some more sources because some Christians are arguing and saying that the Author used false stories to defend our Prophet (SAW) for that reason i need more sources so that i can shut their mouth up!