The phrase "the covenant decrees" refers to the box that held the tablets that the covenant decrees were written on. AT: "the ark of the covenant" or "the box that holds the covenant decrees" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
# the staff of the man whom I choose will bud
"buds will start to grow on the staff of the man whom I choose"
# cause the complaints from the people of Israel to stop, which they are speaking against you
Here "complaints" is an abstract noun that can be expressed as a verb. AT: "make the people of Israel stop complaining against you" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])