Book of Mormon Verses:
3 Nephi 12:38-39
(Parallel to Matthew 5 — the Sermon on the Mount as delivered to the Nephites by the resurrected Christ)

"And behold, it is written, an eye for an eye, and a tooth for a tooth.
But I say unto you, that ye shall not resist evil, but whosoever shall smite thee on thy right cheek, turn to him the other also."

Mosiah 23:15
"Thus did Alma teach his people, that every man should love his neighbor as himself, that there should be no contention among them."

Mosiah 2:32-33
"...that ye should not transgress, that the punishment of God should not come upon you. It is better that ye should deny yourselves of these things, wherein ye will take up your cross, than that ye should be cast into hell..."

This passage discourages sinful behavior (like revenge) and emphasizes turning to God rather than taking matters into one’s own hands.

Alma 48:23
"Now they were sorry to take up arms against the Lamanites, because they did not delight in the shedding of blood; yea, and this was not all—they were sorry to be the means of sending so many of their brethren out of this world..."

This verse reflects a moral reluctance toward violence, even in justified war, and a broader ethic of mercy.

Doctrine and Covenants (D&C):
Doctrine and Covenants 98:23-24
"Now, I speak unto you concerning your families—if men will smite you, or your families, once, and ye bear it patiently and revile not against them, neither seek revenge, ye shall be rewarded;
But if ye bear it not patiently, it shall be accounted unto you as being meted out as a just measure unto you."

Doctrine and Covenants 64:9-10
"Wherefore, I say unto you, that ye ought to forgive one another; for he that forgiveth not his brother his trespasses standeth condemned before the Lord...
I, the Lord, will forgive whom I will forgive, but of you it is required to forgive all men."