আল-মায়িদাহ
You will surely find the most intense of the people in animosity toward the believers [to be] the Jews and those who associate others with Allāh; and you will find the nearest of them in affection to the believers those who say, "We are Christians." That is because among them are priests and monks and because they are not arrogant.
Allāh will not impose blame upon you for what is meaningless in your oaths, but He will impose blame upon you for [breaking] what you intended of oaths. So its expiation is the feeding of ten needy people from the average of that which you feed your [own] families or clothing them or the freeing of a slave. But whoever cannot find [or afford it] - then a fast of three days [is required]. That is the expiation for oaths when you have sworn. But guard your oaths. Thus does Allāh make clear to you His verses [i.e., revealed law] that you may be grateful.