נֹצֵ֥ר חֶ֙סֶד֙ לָאֲלָפִ֔ים נֹשֵׂ֥א עָוֺ֛ן וָפֶ֖שַׁע וְחַטָּאָ֑ה וְנַקֵּה֙ לֹ֣א יְנַקֶּ֔ה פֹּקֵ֣ד ׀ עֲוֺ֣ן אָב֗וֹת עַל־בָּנִים֙ וְעַל־בְּנֵ֣י בָנִ֔ים עַל־שִׁלֵּשִׁ֖ים וְעַל־רִבֵּעִֽים׃
yang memelihara kasih setia bagi beribu-ribu keturunan, yang mengampuni kejahatan, pemberontakan, dan dosa, namun sekali-kali tidak membebaskan begitu saja dari hukuman; yang membalaskan kejahatan para bapa kepada anak-anak dan kepada cucu-cucu, kepada keturunan ketiga dan keempat.”
Rashi
נצר חסד means God keeps (stores up) the mercy which a person does in His presence,
Chizkuni
נושא עון ופשע, “He welcomes the penitent, even those who sinned deliberately or out of obstinacy.”
Da'at Zekenim
נוצר חסד לאלפים, “extending kindness to a thousand generations;” G–d undertakes to extend kindness to the descendants of the good and righteous fathers even of sinners. This concept has been repeated in Deuteronomy 7,9: where a time limit of one thousand generations is the limit. Rash’bam explains the apparent contradiction with our verse where the word לאלפים appears to mean at least two thousand, that we find, grammatically speaking, that a fourth generation, normally described as דור רביעי, is on occasion described as רבעים, with the plural mode ending. The same is true here. (Compare our verse) Therefore אלף or אלפים, can mean the same thing on occasion.