2 Peter 3:9 (BSB)

The Lord is not slow in keeping His promise as some understand slowness, but is patient with you, not wanting anyone to perish but everyone to come to repentance.

From 2 Peter 3. Also in the ESV.

Commentary on 2 Peter 3:9

• John Calvin (Reformed), Calvin's Commentaries on 2 Peter 3:9: 9. But the Lord is not slack, or, delays not. He checks extreme and unreasonable haste by another reason, that is, that the Lord defers his coming that he might invite all mankind to repentance. For our minds are always prurient, and a doubt often creeps in, why he does not come sooner.
• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on 2 Peter 3:9-10: We are here told that the Lord is not slack - he does not delay beyond the appointed time; as God kept the time that he had appointed for the delivering of Israel out of Egypt, to a day (Exo 12:41), so he will keep to the time appointed in coming to judge the world.
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on 2 Peter 3:9: The Lord is not slack concerning his promise,.... The Syriac version reads in the plural, "his promises", any of his promises; though the words seem rather to regard the particular promise of Christ's coming, either to take vengeance on the Jewish nation, of which coming there was a promise made, and is often referred to by Christ, and his apostles; see Mar 9:1 Heb 10:37...
• Albert Barnes (Presbyterian), Barnes' New Testament Notes on 2 Peter 3:9: Verse 9. The Lord is not slack concerning his promise. That is, it should not be inferred because his promise seems to be long delayed that therefore it will fail. When men, after a considerable lapse of time, fail to fulfil their engagements, we infer that it is because they have changed their plans, or because they have forgotten their promises, or because they have...