Isaiah 50:6
6. smiters—with scourges and with the open hand (Isa 52:14; Mr 14:65). Literally fulfilled (Mt 27:26; 26:27; Lu 18:33). To "pluck the hair" is the highest insult that can be offered an Oriental (2Sa 10:4; La 3:30). "I gave" implies the voluntary nature of His sufferings; His example corresponds to His precept (Mt 5:39).
spitting—To spit in another's presence is an insult in the East, much more on one; most of all in the face (Job 30:10; Mt 27:30; Lu 18:32). Matthew 5:39
39. But I say unto you, That ye resist not evil; but whosoever shall smite thee on thy right check, turn to him the other also—Our Lord's own meek, yet dignified bearing, when smitten rudely on the cheek (Joh 18:22, 23), and not literally presenting the other, is the best comment on these words. It is the preparedness, after one indignity, not to invite but to submit meekly to another, without retaliation, which this strong language is meant to convey.