When she denied having the letter, Ali threatened to undress her. On that she handed over the letter after pulling it out from the top of her head. Umar then intended to kill Habib because of his treachery, but the Holy Prophet did not allow him to do so, as he had participated in the Battle of Badr. The Holy Prophet proceeded from Madina with a strong fighting force of ten thousand fully armed Companions (i.e. Ansar and Muhajireen). All of them were covered with armors. On the way, the representatives of different Muslim tribes joined them.
The Holy Prophet 
with a great speed reached Mar-Azahran, located in the suburbs of Mecca. Such a rapid move wonder struck even his own Companions finding themselves in the suburbs of Mecca, ready to attack the holy city, since only a few of them, who were very close to the Holy Prophet, knew his confidential plan.
At Mar-Azahran, the Holy Prophet ordered every Muslim to burn fire at night so that the Muslim army might look huge and splendid. Abu Sufyan, the leader of Quraish, along with his companion Budeel bin Warqa moved out of Mecca in the later part of that night to get information about the activities of the Holy Prophet. On seeing the fire all around, hestated to his companion that he had never seen such a splendid and huge army before.
In the mean time, Abbas, who was patrolling that area recognized Abu Sufyan and brought him to the Holy Prophet, who granted him security.
The Holy Prophet before marching towards Mecca, ordered his Companions not to fight the people except against those who attacked them. He further instructed Abbas to show Abu Sufyan the Muslim army while proceeding towards Mecca. On being greatly impressed, he rushed towards the people of Mecca on the advice of Abbas and advised them to surrender since they could not face the huge army that he had never seen before.
The people of Mecca surrendered without fighting excepting a minor incident. The Holy Prophetvictoriously entered his birth town, where he granted amnesty to Quraish , who assembled before him in Haram, scared and frightened.
Note: After the conquest of Mecca, the Holy Prophet circumambulated Kaba (seven times) and then addressed the audience as below:
La ilaha illa-Allah-o; wahdahu, la shareekalahu, saqa wadahu,
wa nasara abdahu, wa hazamal ahzaba wahdahu…”
