The Holy Spirit is there as an intermediary when the words won’t come.  It might be devastating news from a friend, or maybe it’s a bad report from the Doctor we’ve just received …either way, we sit numb and silent before God.  It’s during those times of infirmity of the body and soul that the Holy Spirit intervenes, imparting the knowledge of divine truth on our behalf.  For we may not have the words to pray…but He does.