en_tn/exo/31/13.md

You must certainly keep Yahweh's Sabbath days

God speaks of obeying his instructions about the Sabbath as keeping the Sabbath. Alternate translation: "You must certainly obey Yahweh's instructions about the Sabbath" (See: rc://en/ta/man/translate/figs-metaphor)

throughout your people's generations

"through all the generations of your descendants." See how you translated this in Exodus 12:14.

who sets you apart for himself

God speaks of choosing people to be his as setting them apart for himself. Alternate translation: "who has chosen you to be his people" (See: rc://en/ta/man/translate/figs-metaphor)