Legacy of Mubahila and a great victory for Islam
The Christians were baffled and amazed, even bewildered. They were impressed with the sincerity of the Prophet (pbuh) and his answers; and his fine qualities gained their trust.
Since a verse for Mubahila, i.e., a challenge with a Du'aa or prayer, had been revealed to the Prophet (pbuh), he suggested doing so in case they did not believe him.
And unto him who disputes with you therein, after the knowledge has come unto you, Say! come you, let us summon our sons and your sons, and our women and your women, and ourselves and yourselves and then let us invoke and lay the curse of God on the liars! (Quran 3:61).
A Mubahila is a spiritual contest. It means that each of the two groups would pray to the Almighty asking for His damnation on those who are false (telling lies). If Mubahila were done, and Prophet Muhammad (pbuh) was saying the truth, then Allah would doom the Christian group and whatever Allah chooses to do to them would come to be! The Patriarch agreed to the Mubahila, and it was to be done at a certain place and time.
A large crowd gathered for the occasion on the specified day. Prophet Muhammad (pbuh) with the 6-year-old Al-Hassan (AS) and the 5-year-old Al-Hussain (AS), each holding one of his hands, and Ali (AS) and his wife Fatima (SA) following, proceeded to the place for Mubahila. The four were the dearest and closest to the heart of the Prophet (pbuh). The Prophet (pbuh) did not choose a wife of his, an aunt, an uncle, a companion or anyone else; instead, he chose Ahl ul-Bayt. Muhammad (pbuh) took them because they represented to him the very essence and the highest in honor since the verse said Our children — and he took Al Hasan and Al Husain; The verse said Our ladies —and he took his daughter Fatima; The verse said: Ourselves — and he took Ali as if Ali was the self of the Prophet.
Upon seeing this group, the Patriarch became startled, even frightened! Taken aback he hurriedly consulted with his group. It became unquestionably obvious that Muhammad (pbuh) was saying only the truth, otherwise he would have brought other than the closest people to him. Thus, they reasoned that for Muhammad (pbuh) to call upon Allah for a curse would certainly bring the damnation and ruin on these Christians. They knew Allah would respond to a Prophet, and by conducting the Mubahila their lot would be ruined!
Having thus debated the matter, the Patriarch came forth with a look of relief. He acknowledged to Muhammad (pbuh) and opted for immediate withdrawal from the Mubahila! The Patriarch also said: “If it weren't for my obligations with the Emperor, I would have right away converted to Islam!”