While he yet spake, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is (c) my beloved Son, in whom I am well pleased; hear ye him.
(c) The word "my" distinguishes Christ from other children. For he is God's natural son, we by adoption; therefore he is called the first begotten among the brethren, because although he is by right the only son, yet he is chief among many, in that he is the source and head of the adoption.