20 This is the first occurrence of the word בְּרִית (bérit, “covenant”) in the Book of Deuteronomy but it appears commonly hereafter (4:23, 31; 5:2, 3; 7:9, 12; 8:18; 9:9, 10, 11, 15; 10:2, 4, 5, 8; 17:2; 29:1, 9, 12, 14, 15, 18, 21, 25; 31:9, 16, 20, 25, 26; 33:9). Etymologically, it derives from the notion of linking or yoking together. See M. Weinfeld, 2:255.
21 Heb “the ten words.”

In other versions

And he declared to you his covenant, which he commanded you to perform, that is, the Ten Commandments, and he wrote them on two tablets of stone.

He declared to you his covenant, the Ten Commandments, which he commanded you to follow and then wrote them on two stone tablets.

He declared his covenant to you. He commanded you to follow the Ten Commandments, which he wrote on two stone tablets.

He proclaimed his covenant—the Ten Commandments—which he commanded you to keep, and which he wrote on two stone tablets.

And he declared to you his covenant, the Ten Commandments, which he charged you to observe, and he wrote them on the two tablets of stone.

And he declared unto you his covenant, which he commanded you to perform, even ten commandments; and he wrote them upon two tables of stone.

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