Êxodo 20:6

and He keeps (stores up) the mercy which a person does to give a reward for it to the thousand generations of that person’s descendants. It follows, therefore, that the measure of good (reward) is greater than the measure of punishment in the proportion of one to five hundred, for the former is threatened only to four generations whilst the latter is bestowed upon thousands (two thousands at least) (Tosefta Sotah 4:1; see Rashi on Exodus 34:7).

KOREN

but showing mercy to thousands of generations of those that love me, and keep my commandments.

MASORETIC

וְעֹ֥֤שֶׂה חֶ֖֙סֶד֙ לַאֲלָפִ֑֔ים לְאֹהֲבַ֖י וּלְשֹׁמְרֵ֥י מִצְוֺתָֽי׃ {ס}