Theophylact of Ohrid
Catena Aurea · Markusevangelium 9
And John answered him, saying, Master, we saw one casting out devils in thy name, and he followeth not us: and we forbad him, because he followeth not us. But Jesus said, Forbid him not: for there is no man which shall do a miracle in my name, that can lightly speak evil of me. For he that is not against us is on our part. For whosoever shall give you a cup of water to drink in my name, because ye belong to Christ, verily I say unto you, he shall not lose his reward. And whosoever shall offend one of these little ones that believe in me, it is better for him that a millstone were hanged about his neck, and he were cast into the sea.
Not only will I not forbid him who works miracles in My name, but also whosoever shall give you the smallest thing for My name’s sake, and shall receive you, not on account of human and worldly favour, but from love to Me, shall not lose his reward.