A.T. Robertson Commentary John 18:11

"Jesus therefore said unto Peter, Put up the sword into the sheath: the cup which the Father hath given me, shall I not drink it?" — John 18:11 (ASV)

Into the sheath (εις την θηκην). Old word from τιθημ, to put for box or sheath, only here in N.T. In Mt 26:52 Christ's warning is given.

The cup (το ποτηριον). Metaphor for Christ's death, used already in reply to request of James and John (Matthew 20:22) and in the agony in Gethsemane before Judas came (Matthew 26:39; Luke 22:42), which is not given by John. The case of το ποτηριον is the suspended nominative for note αυτο (it) referring to it.

Shall I not drink? (ου μη πιω; ). Second aorist active subjunctive of πινω with the double negative ου μη in a question expecting the affirmative answer. Abbott takes it as an exclamation and compares 6:37; Mr 14:25.