The party returned to Medina and the Prophet(sa) and his followers started preparations for migration. Family after family began to disappear. Muslims, certain that the Kingdom of God was near, were full of courage. Sometimes a whole lane would be emptied in the course of a night. In the morning Meccans would see the doors locked and realize that the residents had migrated to Medina. The growing influence of Islam amazed them.
At last not a single Muslim remained in Mecca save a few slave converts, the Prophet(sa) himself, Abu Bakr(ra) and Ali(ra). The Meccans realized that their prey was about to escape. The chiefs assembled again and decided they should now kill the Prophet(sa). By a special divine design, it seems, the date they appointed for killing the Prophet(sa) was appointed for his escape. When the Meccan party was collecting in front of the Prophet's(sa) house with intent to kill, the Prophet(sa) was moving out in the secrecy of the night. The Meccans must have feared anticipation of their foul design by the Prophet(sa). They proceeded cautiously and when the Prophet(sa) himself passed by, they took him for someone else, and withdrew to avoid being noticed. The Prophet's(sa) closest friend Abu Bakr(ra) had been informed of the Prophet's(sa) plan the day before. He duly joined and then both left Mecca, and took shelter in a cave called Thaur, about three or four miles from Mecca over a hill. When the Meccans learnt of the Prophet's(sa) escape, they collected and sent a force in pursuit. Led by a tracker, they reached Thaur. Standing at the mouth of the cave in which the Prophet(sa) and Abu Bakr(ra) sat hiding, the tracker said that Muhammad(sa) was either in the cave or had ascended to heaven. Abu Bakr(ra) heard this and his heart sank. "The enemy has nearly got us," he whispered. "Fear not, God is with us," replied the Prophet(sa). "I fear not for myself," went on Abu Bakr(ra), "but for you. For, if I die, I am but an ordinary mortal; but if you die, it will mean death to faith and spirit" (Zurqani). "Even so, fear not," assured the Prophet(sa), "We are not two in this cave. There is a third—God" (Bukhari).
Meccan tyranny was destined to end. Islam was to have the chance to grow. The pursuers were deceived. They ridiculed the tracker's judgement. It was too open a cave, they said, for anybody to take shelter in, for with snakes and vipers it was none too safe. If they had but bent a little, they could have sighted the two. But they did not, and dismissing the tracker, they returned to Mecca.
For two days the Prophet(sa) and Abu Bakr(ra) waited in the cave. On the third night, according to the plan, two fleet camels were brought to the cave, one for the Prophet(sa) and the guide; the other for Abu Bakr(ra) and his servant, Amir bin Fuhaira(ra).