18 Literally “doing loyal love” (עֹשֶׂה חֶסֶד, ’oseh khesed). The noun refers to God’s covenant loyalty, his faithful love to those who belong to him. These are members of the covenant, recipients of grace, the people of God, whom God will preserve and protect from evil and its effects.
19 Heb “to thousands” or “to thousandth.” After “tenth,” Hebrew uses cardinal numbers for ordinals also. This statement is the antithesis of the preceding line. The “thousands” or “thousandth [generation]” are those who love Yahweh and keep his commands. These are descendants from the righteous, and even associates with them, who benefit from the mercy that God extends to his people. S. R. Driver (Exodus, ) says that this passage teaches that God’s mercy transcends his wrath; in his providence the beneficial consequences of a life of goodness extend indefinitely further than the retribution that is the penalty for persisting in sin. To say that God’s loyal love extends to thousands of generations or the thousandth generation is parallel to saying that it endures forever (Ps. 118). See also Exod 34:7; Deut 5:10; 7:9; Ps 18:51; Jer 32:18.

In other versions

but showing steadfast love to thousands of those who love me and keep my commandments.

but showing love to a thousand generations of those who love me and keep my commandments.

but showing faithful love to a thousand generations of those who love me and keep my commands.

But I lavish unfailing love for a thousand generations on those who love me and obey my commands.

and showing loyal love to thousands of generations of those loving me and of those keeping my commandments.

And shewing mercy unto thousands of them that love me, and keep my commandments.

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