{And I will pray the Father} (kag(9320)er(9374)(8873)(9320)ton patera).
Er(9374)a(935c) for prayer, not question (the old use), also in  16:23 
(prayer to Jesus in same sense as aite(935c)),  26  (by Jesus as
here);  17:9  (by Jesus), "make request of." {Another Comforter}
(allon parakl(8874)on). Another of like kind (allon, not
heteron), besides Jesus who becomes our Paraclete, Helper,
Advocate, with the Father ( 1Jo 2:1 , Cf.  Ro 8:26f. ). This old
word (Demosthenes), from parakale(935c), was used for legal
assistant, pleader, advocate, one who pleads another's cause
(Josephus, Philo, in illiterate papyrus), in N.T. only in John's
writings, though the idea of it is in  Ro 8:26-34 . Cf.
Deissmann, _Light, etc._, p. 336. So the Christian has Christ as
his Paraclete with the Father, the Holy Spirit as the Father's
Paraclete with us ( Joh 14:16,26  15:26  16:7  1Jo 2:1 ). {For
ever} (eis ton ai(936e)a). This the purpose (hina) in view and
thus Jesus is to be with his people here forever ( Mt 28:20 ).
See  4:14  for the idiom.