"At that day ye shall ask in My name," i.e., in My nature. Not – "You shall use My name as a magic word," but – "You will be so intimate with Me that you will be one with Me." "That day" is not a day hereafter, but a day meant for here and now. "The Father Himself loveth you" – the union is so complete and absolute. Our Lord does not mean that life will be free from external perplexities, but that just as He knew the Father’s heart and mind, so by the baptism of the Holy Ghost He can lift us into the heavenly places where He can reveal the counsels of God to us.
"Whatsoever ye shall ask the Father in My name. . . ." "That day" is a day of undisturbed relationship between God and the saint. Just as Jesus stood unsullied in the presence of His Father, so by the mighty efficacy of the baptism of the Holy Ghost, we can be lifted into that relationship – "that they may be one, even as We are One."
"He will give it you." Jesus says that God will recognize our prayers. What a challenge! By the Resurrection and Ascension power of Jesus, by the sent-down Holy Ghost, we can be lifted into such a relationship with the Father that we are at one with the perfect sovereign will of God by our free choice even as Jesus was. In that wonderful position, placed there by Jesus Christ, we can pray to God in His name, in His nature, which is gifted to us by the Holy Ghost, and Jesus says – "What soever ye shall ask the Father in My name, He will give it you." – The sovereign character of Jesus Christ is tested by His own statements.