Tertullian

With us, however, the Son alone knows the Father, and has Himself unfolded "the Father's bosom." He has also heard and seen all things with the Father; and what He has been commanded by the Father, that also does He speak. And it is not His own will, but the Father's, which He has accomplished, which He had known most intimately, even from the beginning. "For what man knoweth the things which be in God, but the Spirit which is in Him? " But the Word was formed by the Spirit, and (if I may so express myself) the Spirit is the body of the Word.