Theophylact of Ohrid
Catena Aurea · Johannesevangelium 12
Jesus cried and said, He that believeth on me, believeth not on me, but on him that sent me. And he that seeth me seeth him that sent me. I am come a light into the world, that whosoever believeth on me should not abide in darkness. And if any man hear my words, and believe not, I judge him not: for I came not to judge the world, but to save the world. He that rejecteth me, and receiveth not my words, hath one that judgeth him: the word that I have spoken, the same shall judge him in the last day. For I have not spoken of myself; but the Father which sent me, he gave me a commandment, what I should say, and what I should speak. And I know that His commandment is life everlasting: whatsoever I speak therefore, even as the Father said unto me, so I speak.
Since the Son is the Word of the Father, and reveals completely what is in the mind of the Father, He says He receives a commandment what He should say, and what He should speak: just as our word, if we say what we think, brings out what is in our minds.