((We take our) colour from Allah, and who is better than Allah at colouring…) [2:138].
Said Ibn ‘Abbas: “When a child was born into the Christians, they used to baptize him on the seventh day by dipping him in holy water in order to purify him. They claimed that this baptism takes the place of circumcision. Upon doing this, they used to say: ‘Now the child has become a true Christian’, and so Allah, exalted is He, revealed this verse”.
Asbab Al-Nuzul by Al-Wahidi , trans. Mokrane Guezzou