Chapter 64.—In What Sense the Holy Spirit Solicits for Us, Crying, Abba, Father.
And this especially since “we know not what to pray for as we ought,” says the apostle, “but the Spirit Himself maketh intercession for us with groanings that cannot be uttered; and He that searcheth the hearts knoweth what is the mind of the Spirit, because He maketh intercession for the saints according to God.” 3708 What is “the Spirit Himself maketh intercession,” but, “causes to make intercession,” “with groanings that cannot be uttered,” but “truthful,” since the Spirit is truth? For He it is of whom the apostle says in another place, “God hath sent the Spirit of His Son into our hearts, “crying, Abba, Father!” 3709 And here what is the meaning of “crying,” but “making to cry,” by that figure of speech whereby we call a day that makes people glad, a glad day? And this he makes plain elsewhere when he says, “For you have not received the Spirit of bondage again in fear, but you have received the Spirit of the adoption of sons, in whom we cry, Abba, Father.” 3710 He there said, “crying,” but here, “in whom we cry;” opening up, that is to say, the meaning with which he said “crying,”—that is, as I have already explained, “causing to cry,” when we understand that this is also itself the gift of God, that with a true heart and spiritually we cry to God. Let them, therefore, observe how they are mistaken who think that our seeking, asking, knocking is of ourselves, and is not given to us; and say that this is the case because grace is preceded by our merits; that it follows them when we ask and receive, and seek and find, and it is opened to us when we knock. And they will not understand that this is also of the divine gift, that we pray; that is, that we ask, seek, and knock. For we have received the spirit of adoption of sons, in which we cry, Abba, Father. And this the blessed Ambrose also said. 3711 For he says, “To pray to God also is the work of spiritual grace, as it is written, No one says, Jesus is the Lord, but in the Holy Spirit.”
Ambrose, Commentary on Isaiah.