(He created him from dust, then (He) said to him: "Be!" and he was.)
Therefore, He Who created Adam without a father or a mother is able to create `Isa, as well, without a father. If the claim is made that `Isa is Allah's son because he was created without a father, then the same claim befits Adam even more. However, since such a claim regarding Adam is obviously false, then making the same claim about `Isa is even more false.
As stated earlier, verse 61 has instructed the Holy Prophet ﷺ to invite his opponents (Christians) to Mubahalah which literally means 'mutual prayer' but in the terminology of Islamic Shari'ah it refers to a particular form of resolving religious disputes. When the argumentations from both sides fail to resolve a religious issue, the parties jointly pray Allah to cast His curse on whichever of the two parties is parties is false. Since curse means 'moving someone far away from the divine mercy', - and moving far away from mercy is being close to divine wrath--therefore, the essence of the meaning is: Wrath be on the liar. As such, whoever is the liar shall face the evil consequences whereupon the truth will become evident before the disbelievers as well. Invocation in this manner is called 'Mubahalah'.
Najran (about 150 miles north of Sana‘ towards Yemen) was a great centre of Christianity at the time of the revelation of the Quran. In the 10th year of the Hijra, a Christian deputation came from Najran, to discuss Christian beliefs with the Prophet Muhammad. The Prophet presented many arguments to them. He asked how Christ could be God’s son, when God is a living being who would never die, whereas Jesus would eventually be overcome by death. They could not counter his arguments but, nevertheless, stood their ground. When the Prophet saw that they were not going to accept his arguments, however sound they might be, he gave them a final challenge. He said that if they really believed that they were right (in believing Christ to be the son of God) they should be ready for a mubahalah, i.e., a solemn meeting, in which both sides should summon not only their men, but their women and children, to pray earnestly to God, and invoke the curse of God on those who lied. Those who were pure and sincere in their faith would not hesitate. The next day the Prophet came out of his home accompanied by his grandsons, Hasan and Husayn, and his daughter Fatimah, and son-in-law ‘Ali. On seeing this the Christians were so impressed that they sought some time to reconsider. In their consultations one of their religious scholars said: ‘You know God has promised to send a Prophet among the Ishmaelites. Suppose he be the same prophet. In that case, the only result of engaging in a mubahalah with him would be the destruction of all our people and its effect would even extend to our next generations. By God, I am seeing such faces as could move mountains with their prayers. So it is better to enter into certain peace treaties with him and go back to our homes.’
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.
