en_tn/lev/23/08.md

will present a food offering

They would present it to Yahweh by burning it on the altar.

The seventh day is an assembly set apart to Yahweh

The requirement that people assemble on that day is spoken of as if that day were the assembly. Being set apart to Yahweh means that when they assemble, they must worship Yahweh. AT: "The seventh day is a day when you must assemble together to worship Yahweh" (See: rc://en/ta/man/translate/figs-metonymy)