This can be translated as an indirect quotation. AT: "and he tells you to serve and worship other gods which you have not known, do not" (See: [[rc://en/ta/man/translate/figs-quotations]])
Worshiping other gods is spoken of as if they were going after or following other gods. AT: "Let us follow other gods" (See: [[rc://en/ta/man/translate/figs-metaphor]])
The phrase "gods, that you have not known" refers to the gods that other people groups worship. The Israelites know Yahweh because he has revealed himself to them and they have experienced his power.
Here "heart" and "soul" are metonyms for a person's inner being. These two phrases are used together to mean "completely" or "earnestly." See how you translated this in [Deuteronomy 4:29](../04/29.md). (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-doublet]])