When the Holy Prophet migrated to Yathrib he left his family at Makkah. When the Muslims had settled in Yathrib (renamed Madina) the Holy Prophet and the other Muslims called their families to Madina. At the time of migration, Sauda an elderly lady was the only wife of the Holy Prophet whom he had married after the death of Khadija. About a year after his arrival in Madina, the Holy Prophet married Ayesha, a daughter of Abu Bakr.
By this time, Fatima, the youngest daughter of the Holy Prophet had come of marriageable age, and the Holy Prophet had to consider the question of her marriage. Abu Bakr waited on the Holy Prophet, and asked for the hand of Fatima. The Holy Prophet made no answer. Thereafter Umar asked for the hand of Fatima and the Holy Prophet maintained silence. In the Arabian society of the day, the disparity in the age of the bride and the bridegroom did not matter. The Holy Prophet married Khadija when he was twenty-five and she was forty, fifteen years older than him. Later the Holy Prophet, when over fifty, married Ayesha yet within her teens. When the Holy Prophet did not respond to the requests of Abu Bakr or Umar he was not bothered about the age question; his silence was due to the fact that he had to wait for the guidance of God which was wont to get in all matters of importance affecting his person.
After the Battle of Badr, Ali made his suit. The Holy Prophet told Ali that he would give his reply after consulting Fatima. The Holy Prophet consulted Fatima, and she maintained silence signifying her assent. In the meantime the Holy Prophet received the revelation that God approved of the marriage of Fatima with Ali. When Fatima the mother of Ali called on the Holy Prophet to press the suit on behalf of Ali, the Holy Prophet was pleased to announce his acceptance.