Sahih Bukhari Volume 5, Book 58, Hadith Number 275.

Narated By Anas : When the news of the arrival of the Prophet at Medina reached ‘Abdullah bin Salam, he went to him to ask him about certain things, He said, “I am going to ask you about three things which only a Prophet can answer: What is the first sign of The Hour? What is the first food which the people of Paradise will eat? Why does a child attract the similarity to his father or to his mother?” The Prophet replied, “Gabriel has just now informed me of that.” Ibn Salam said, “He (i.e. Gabriel) is the enemy of the Jews amongst the angels. The Prophet said, “As for the first sign of The Hour, it will be a fire that will collect the people from the East to the West. As for the first meal which the people of Paradise will eat, it will be the caudate (extra) lobe of the fish-liver. As for the child, if the man’s discharge proceeds the woman’s discharge, the child attracts the similarity to the man, and if the woman’s discharge proceeds the man’s, then the child attracts the similarity to the woman.”

On this, ‘Abdullah bin Salam said, “I testify that None has the right to be worshipped except Allah, and that you are the Apostle of Allah.” and added, “O Allah’s Apostle! Jews invent such lies as make one astonished, so please ask them about me before they know about my conversion to Islam.” The Jews came, and the Prophet said, “What kind of man is ‘Abdullah bin Salam among you?” They replied, “The best of us and the son of the best of us and the most superior among us, and the son of the most superior among us. “The Prophet said, “What would you think if ‘Abdullah bin Salam should embrace Islam?” They said, “May Allah protect him from that.” The Prophet repeated his question and they gave the same answer. Then ‘Abdullah came out to them and said, “I testify that None has the right to be worshipped except Allah and that Muhammad is the Apostle of Allah!” On this, the Jews said, “He is the most wicked among us and the son of the most wicked among us.” So they degraded him. On this, he (i.e. ‘Abdullah bin Salam) said, “It is this that I was afraid of, O Allah’s Apostle.