Can people hold on to their anger
against others, and then look for healing from the Lord?
Can they refuse to have mercy
on people like themselves,
and then pray about their own sins?
If they, who are just flesh,
hold on to anger,
who will secure pardon
for their own sins?

[ἄνθρωπος ἀνθρώπῳ συντηρεῖ ὀργήν,
καὶ παρὰ κυρίου ζητεῖ ἴασιν;
ἐπ᾽ ἄνθρωπον ὅμοιον αὐτῷ οὐκ ἔχει ἔλεος,
καὶ περὶ τῶν ἁμαρτιῶν αὐτοῦ δεῖται;
αὐτὸς σὰρξ ὢν διατηρεῖ μῆνιν,
τίς ἐξιλάσεται τὰς ἁμαρτίας αὐτοῦ;]

The Bible (The Old Testament) (14th - 2nd C BC) Judeo-Christian sacred scripture [Tanakh, Hebrew Bible], incl. the Apocrypha (Deuterocanonicals)

Book 22b. Sirach (Ecclesiasticus) 28: 3ff (Sir 28:3–5) [tr. CEB (2011)]
    (Source)

More on the history and acceptance of this Apocryphal book here and here.

(Source (Greek)). Alternate translations:

One man beareth hatred against another, and doth he seek pardon from the Lord?
He sheweth no mercy to a man, which is like himself: and doth he ask forgiveness of his own sins?
If he that is but flesh nourish hatred, who will intreat for pardon of his sins?
[tr. KJV (1611)]

Man to man reserveth anger, and doth he seek remedy of God?
He hath no mercy on a man like himself, and doth he entreat for his own sins?
He that is but flesh, nourisheth anger, and doth he ask forgiveness of God? who shall obtain pardon for his sins?
[tr. DRA (1899)]

If a man nurses anger against another,
can he then demand compassion from the Lord?
Showing no pity for a man like himself,
can he then plead for his own sins?
Mere creature of flesh, he cherishes resentment;
who will forgive him his sins?
[tr. JB (1966)]

If anyone nurses anger against another,
can one then demand compassion from the Lord?
Showing no pity for someone like oneself,
can one then plead for one's own sins?
Mere creature of flesh, yet cherishing resentment!
-- who will forgive one for sinning?
[tr. NJB (1985)]

You cannot expect the Lord to pardon you while you are holding a grudge against someone else. You yourself are a sinner, and if you won't forgive another person, you have no right to pray that the Lord will forgive your sins. If you cannot get rid of your anger, you have no hope of forgiveness — you are only a human being.
[tr. GNT (1992 ed.)]

Does anyone harbor anger against another
and expect healing from the Lord?
If people have no mercy toward those like themselves,
can they then seek pardon for their own sins?
If mere mortals harbor wrath,
who will make an atoning sacrifice for their sins?
[tr. NRSV (2021 ed.)]