申命記 7:9

לאלף דור TO A THOUSAND GENERATIONS — But elsewhere (5:10) it states: to thousands of generations! The explanation is: Here where it is connected with (refers to) "those who keep His commandments" it states that God's grace is extended to a thousand generations; but there where it is associated with "those who love Him" it states that it is extended to thousands of generations (Sotah 31a); לאהביו are those who do the commandments out of love. ולשמרי מצותיו are those who do them out of fear.

וְיָ֣דַעְתָּ֔ כִּֽי־יְהֹוָ֥ה אֱלֹהֶ֖יךָ ה֣וּא הָֽאֱלֹהִ֑ים הָאֵל֙ הַֽנֶּאֱמָ֔ן שֹׁמֵ֧ר הַבְּרִ֣ית וְהַחֶ֗סֶד לְאֹהֲבָ֛יו וּלְשֹׁמְרֵ֥י מִצְוֺתָ֖ו לְאֶ֥לֶף דּֽוֹר׃

Know therefore that the Lord thy God, he is God, the faithful God, who keeps covenant and troth with those who love him and keep his commandments to a thousand generations;