The phrase "the covenant decrees" refers to the box that held the tablets that the covenant decrees were written on. Alternate translation: "the ark of the covenant" or "the box that holds the covenant decrees" (See: [[rc://en/ta/man/jit/figs-synecdoche]])
The word "complaints" is an abstract noun that can be expressed as a verb. Alternate translation: "so that you may stop them from complaining against me" (See: [[rc://en/ta/man/jit/figs-abstractnouns]])