John Gill Commentary Luke 6:29

"To him that smiteth thee on the [one] cheek offer also the other; and from him that taketh away thy cloak withhold not thy coat also." — Luke 6:29 (ASV)

And unto him that smiteth thee on the one cheek
The right cheek,

offer also the other ;
the left cheek, by turning it to him, that he may smite that likewise, if he thinks fit: by which proverbial expression, Christ teaches patience in bearing injuries and affronts, and not to seek private revenge; but rather, suffer more, than indulge such a temper; and for the same purpose is what follows urged:

and him that taketh away thy cloak, forbid not to take thy coat also :
the phrase is inverted in Matthew;(See Gill on :)(See Gill on :)