Musnad Ahmad 25:1059

Hashim ibn al-Qasim narrated to us, Shayban narrated to us, from ‘Asim, from Abu Razin, from Abu Yahya, the freed slave of Ibn ‘Aqil al-Ansari, who said: Ibn ‘Abbas said: "I have known a verse of the Qur’an about which no man has ever asked me. I do not know if people know it and therefore did not ask about it, or if they did not perceive it and therefore did not ask about it." Then he began to speak to us. When he stood up, we blamed one another for not having asked him about it. I said: "I will take care of it when he comes tomorrow." When he came the next day, I said: "O Ibn ‘Abbas, you mentioned yesterday that there is a verse of the Qur’an about which no man has ever asked you, and you do not know if people know it and therefore did not ask about it, or if they did not perceive it and therefore did not ask about it. So tell me about it, and about those that were recited before it." He said: "Yes. The Messenger of Allah (peace and blessings of Allah be upon him) said to Quraysh: 'O assembly of Quraysh, there is no one worshipped besides Allah in whom there is any good.' Quraysh knew that the Christians worshipped ‘Isa ibn Maryam, and what they said about Muhammad. So they said: 'O Muhammad, do you not claim that ‘Isa was a prophet and a righteous servant from among the servants of Allah? If you are truthful, then their gods are just as you say.' He said: "Then Allah, the Mighty and Majestic, revealed: {And when the son of Mary was presented as an example, behold, your people laugh at it} [Az-Zukhruf: 57]." I said: "What does 'laugh at it' (yassuddun) mean?" He said: "They clamor. {And indeed, it [i.e., ‘Isa] will be [a sign for] knowledge of the Hour} [Az-Zukhruf: 61]." He said: "It is the emergence of ‘Isa ibn Maryam (peace be upon him) before the Day of Resurrection."