Al-Baqara • EN-ASBAB-AL-NUZUL-BY-AL-WAHIDI
﴿ أَمْ كُنتُمْ شُهَدَآءَ إِذْ حَضَرَ يَعْقُوبَ ٱلْمَوْتُ إِذْ قَالَ لِبَنِيهِ مَا تَعْبُدُونَ مِنۢ بَعْدِى قَالُوا۟ نَعْبُدُ إِلَٰهَكَ وَإِلَٰهَ ءَابَآئِكَ إِبْرَٰهِۦمَ وَإِسْمَٰعِيلَ وَإِسْحَٰقَ إِلَٰهًۭا وَٰحِدًۭا وَنَحْنُ لَهُۥ مُسْلِمُونَ ﴾
“Nay, but you [yourselves, O children of Israel,] bear witness that when death was approaching Jacob, he said unto his sons: "Whom will you worship after I am gone?" They answered: "We will worship thy God, the God of thy forefathers Abraham and Ishmael and Isaac, the One God; and unto Him we surrender ourselves."”
(Or were ye present when death came to Jacob�) [2:133]. This was revealed about the Jews when they said: �Do you not know that when Jacob was about to die he advised his sons to follow Judaism?�