(O ye who believe! Come, all of you, into submission (unto Him)…) [2:208].
Abu Nu'aym al-Asfahani informed me, in one of the narration that he authorized me to narrate from him> Sulayman ibn Ahmad> Bakr ibn Sahl> 'Abd al-Ghaniyy ibn Sa'id> Musa ibn 'Abd al-Rahman al-San'ani> Ibn Jurayj> 'Ata'> ibn 'Abbas that he said: “This verse was revealed about 'Abd Allah ibn Salam and his followers. This is because when they believed in the Prophet, Allah bless him and give him peace, they observed the laws that he brought forth while still observing the laws of Moses. They observed the Sabbath and shunned the meat and milk of camels after they embraced Islam. Some Muslims reproached them for this but they defended themselves by saying that they could observe both. They said to the Prophet, Allah bless him and give him peace: 'The Torah is the Book of Allah, so let us observe its teachings'. Allah, exalted is He, then revealed this verse”.
Asbab Al-Nuzul by Al-Wahidi , trans. Mokrane Guezzou