n°45 / The Epistle to the Romans 8 :

25But if we hope for that we see not, then do we with patience wait for it.
26Likewise the Spirit also helpeth our infirmities : for we know not what we should pray for as we ought : but the Spirit itself maketh intercession for us with groanings which cannot be uttered.
27And he that searcheth the hearts knoweth what is the mind of the Spirit, because he maketh intercession for the saints according to the will of God.