It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that a delegation of Jews came to the Prophet (peace and blessings be upon him) and said,“O Abul Qasim (peace and blessings be upon him)! We want to ask you a few questions which no one knows except a Prophet. Please answer them for us.”The Prophet (peace and blessings be upon him) said,“Ask me whatever you wish, but swear to me by Allah and by the covenant that Jacob (peace be upon him) took from his sons, that whatever answer I give you, if you find it correct, you will pledge allegiance to me upon Islam.”They said,“We promise you.”The Prophet (peace and blessings be upon him) said,“Now ask, what do you want to ask?”They said,“We ask you about four things: First, tell us what was the food that Jacob (peace be upon him) made unlawful for himself before the Torah was revealed? Second, tell us about the nature of the fluid of man and woman, and how is a male child born? Third, tell us about the state of sleep of this unlettered Prophet? And fourth, who is the angel who brings revelation to him?”The Prophet (peace and blessings be upon him) said,“Do you swear to me by Allah that if I answer these questions, you will follow me?”They made a very firm covenant with the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) said,“I ask you by the One Who revealed the Torah to Moses (peace be upon him), do you know that once Jacob (peace be upon him) became very ill, and when his illness prolonged, he vowed to Allah that if Allah granted him recovery from this illness, he would make his most beloved drink and most beloved food unlawful for himself? And among those foods, camel meat was the most beloved, and among drinks, camel milk was the most beloved?”They confirmed this. The Prophet (peace and blessings be upon him) said,“O Allah! Bear witness.”Then he said,“I ask you by Allah, besides Whom there is no deity, and Who revealed the Torah to Moses (peace be upon him), do you know that the fluid of a man is white and thick, and the fluid of a woman is yellow and thin? Whichever of the two fluids prevails, by Allah’s command, the child resembles that one. So if the man’s fluid prevails over the woman’s, by Allah’s command, the child is a boy, and if the woman’s fluid prevails over the man’s, by Allah’s command, the child is a girl?”They also confirmed this. The Prophet (peace and blessings be upon him) said,“O Allah! Bear witness.”Then he said,“I ask you by the One Who revealed the Torah to Moses (peace be upon him), do you know that the eyes of this unlettered Prophet sleep, but his heart does not sleep?”They said,“Yes!”The Prophet (peace and blessings be upon him) said,“O Allah! Bear witness.”The Jews then said,“Now tell us, who is the angel who is your friend? Upon this, we will either join you or separate from you.”The Prophet (peace and blessings be upon him) said,“My friend is Jibreel (Gabriel), the Trustworthy, and whichever Prophet Allah sent, he was his friend.”Upon hearing this, the Jews said,“Now we cannot stay with you. If any other angel besides him had been your friend, we would have surely followed you and affirmed you.”The Prophet (peace and blessings be upon him) said,“What prevents you from affirming me in the presence of Jibreel, the Trustworthy?”They said,“He is our enemy.”Upon this, the following verse was revealed: «﴿قُلْ مَنْ كَانَ عَدُوًّا لِجِبْرِيلَ . . . . . كَأَنَّهُمْ لَا يَعْلَمُونَ﴾ [البقرة: 97-101] » “Say: Whoever is an enemy to Gabriel . . . . . as they do not know.”And at that time, they returned carrying anger upon anger from Allah.