en_tn/deu/04/06.md

keep them and do them

These two phrases mean basically the same thing and emphasize that they are to obey them. Alternate translation: "obey them carefully" (See: rc://en/ta/man/jit/figs-doublet)

this is your wisdom and your understanding in the sight of the peoples

The abstract nouns "wisdom" and "understanding" can be translated as adjective phrases, and the abstract noun "sight" refers to how the peoples judge or decide on the value of something. Alternate translation: "this is what will show the peoples that you are wise and that you understand what is important" (See: rc://en/ta/man/jit/figs-abstractnouns and rc://en/ta/man/jit/figs-metaphor)

this great nation is a wise and understanding people

The word "nation" is a metonym for the people of that nation. Alternate translation: "the people of this great nation are wise and understanding" (See: rc://en/ta/man/jit/figs-metonymy)