He (peace be upun him) invited people to Allah day and night, secretly and publicly. He remained in Makkah three years at the beginning of his prophethood, calling for the worship of Allah secretly. But after the verse was revealed saying:
“Then declare what you are commanded and turn away from the polytheists”
He (peace be upun him) complied with the order of Allah without fearing the blame of a critic. He invited the old and the young, freemen and slaves, males and females, human beings and jinn to believe in Allah.
When persecution and torture increased against his companions in Makkah, he allowed them to emigrate to Abyssinia.
He (peace be upun him) went to Taif, hoping to find support. He called them to believe in Allah, but no one responded to him. On the contrary, they abused him even more than his own people and expelled him, returning him to Makkah, where he entered under the protection of Mut`im bin `Adiyy.
He (peace be upun him) continued da`wah openly for ten years, taking advantage of annual seasons and following pilgrims to their camps. He also made da`wah during the trade seasons of Okaz, Majinnah and Dhil-Majaaz and would ask about each tribe and its campsite.
Finally, he (peace be upun him) met six people from the Khazraj tribe at al-Aqabah. He presented Islam to them and they accepted it. Upon returning to Madinah, they invited the people to Islam, and soon it spread until there was no home in which Islam had not entered.
The following year twelve of them came and concluded with him the Pledge of `Aqabah, pledging obedience, financial support and to order what is right and forbid what is wrong. They also pledged to speak about Allah without fearing the reproach of any critic and to aid and protect the Prophet (peace be upun him) as they would protect themselves, their wives and their children in exchange for the reward of Paradise. They returned to Madinah, accompanied by Ibn Umm Maktoum  and Mus`ab bin `Umayr  to teach the Qur'an and call people to Allah. Through their da`wah many people entered Islam, among them Usayd bin Hudhayr and Sa`d bin Mu`adh .
Then he (peace be upun him) allowed Muslims to emigrate to Madinah and they began to do so. He (peace be upun him) and his companion [Abu Bakr  ] later followed them.
He (peace be upun him) established a brotherhood between the Muhajireen and the Ansaar. They were 90 men in all.
a. His Guidance in Security, Reconciliation and Treatment of Emissaries
It is confirmed that the Prophet (peace be upun him) said: “The right of protection is the same for all Muslims; the most humble of them can give it.”
He (peace be upun him) also said: “Whoever enters into a pact with another people must not dissolve it until it expires or they violate it first.”
He (peace be upun him) said: “Whoever gives someone security and then kills him, I am disassociated from the killer.”
When the messengers of Musaylimah approached him, he (peace be upun him) listened to them and then said:
“Was it not that emissaries are not killed, I would have had you beheaded.”
This was his practice: that emissaries should never be killed.
He (peace be upun him) would not detain an emissary if he chose to keep his faith [instead of Islam]; rather, he (peace be upun him) would send him back.
If some of his enemies entered a pact with one of his companions without his approval and it was not harmful to the Muslims, he allowed it.
He (peace be upun him) made a truce of ten years from the state of the war with the Quraysh, on the condition that Muslims who came to him from Quraysh would be sent back, while anyone going from him to Quraysh would not be returned. But Allah cancelled this condition in the case of women, and ordered that when they came to the Prophet (peace be upun him) their faith should be examined. If a woman was found to be a believer she would not be sent back.
If a disbelieving wife chose to join the disbelievers of Quraysh, Allah ordered Muslims to give those whose wives had deserted the equivalent of what they had spent on the wife's mahr (dower). They were to demand it from the disbelievers since the disbelievers had a similar right whenever a believing woman joined the Muslims.
The Prophet (peace be upun him) did not prevent the Quraysh from taking back any men who came to him, but he (peace be upun him) did not compel them to return nor did he order them to. But when some of those men killed or took the property of disbelievers after leaving the Prophet (peace be upun him) and without going back to him, he would neither disapprove of it nor guarantee security from them.
The Prophet (peace be upun him) made a settlement with the Jews of Khaybar after defeating them on condition that they leave the area. They were allowed to take whatever their mounts could carry while the Prophet (peace be upun him) had the right to their gold, silver and weapons.
He (peace be upun him) also settled with them concerning the land: that he would have half of its produce and they would have half, as long as they stayed with his permission. He (peace be upun him) would send someone every year to estimate the value of the crop and see how much was harvested. He (peace be upun him) would get a guarantee of the Muslims’ share and leave them the rest.
b. His Guidance in Da`wah to Rulers and Sending Them Envoys and Letters
When the Prophet (peace be upun him) returned from Hudaybiyyah, he wrote to kings around the world and sent his messengers to them. He addressed the Byzantine emperor by letter and through an emissary. He was inclined to Islam and on the verge of declaring it but he did not.
He (peace be upun him) sent a letter to an-Najashi (the ruler of Abyssinia), who embraced Islam.
