Prophet Muhammad (P.B.U.H.) received revelation from Allah as a prophet at the age of forty. He started to guide the people at the command of Allah.
Prophet Muhammad (P.B.U.H.) at first invited some of his close friends and relatives to Islam.
After a short time, he invited some of the elders of Makkah to his house.
When everyone came to his house he asked them, "Did you ever hear a lie from me?" Everyone replied, "No. You are a truthful and a righteous man. We never heard anything but the truth from you." Prophet Muhammad (P.B.U.H.) continued, "Then know that I am about to tell you another truth; I am the Messenger of Allah. I invite you to the worship of One Allah. You must stop doing evil deeds."
However, they did not want to stop their old ways. For this reason they became angry and left the Prophet's house. When the teachings of the Prophet spread, little by little, many people began to believe in him.
The enemies of Islam disliked the progress of Islam and they turned against it. However, the Muslims stood firm and protected their religion.
When the Prophet saw the idol worshippers treating the Muslims in the most cruel manner, he sent a group of his followers to Abbysinia, a country in Africa, to escape from cruelty, injustice, and to continue spreading the message of Islam.
Muhammad stayed behind in Makkah with some of his other followers. After a short time, the enemies of Islam started to increase their cruelty and war against the Muslims.
They all agreed among themselves not to speak or have anything to do with the Muslims, Muhammad, and the tribe of Bani Hasihm who had been protecting the Prophet from the cruelty and the evil designs of the Quraysh. They also agreed not to pay their debts back to any of the Muslims.
The enemies of the Prophet thought that with cruelty they could stop the Prophet from his mission of inviting people to Islam.
Prophet Muhammad (P.B.U.H.) with his followers and family members (Bani Hashim) were forced to leave the city of Makkah. They left and went to a valley (Shab Abu Talib) near the mountains where there was no food or water. Their enemies would not let anybody bring them any food or water. The Muslims managed to survive through the hardships in the valley and did not give up their religion.
Three years went by after which the idol worshippers of Makkah could not continue with their boycott and had to let the Prophet and his followers return to Makkah.