Here "feet" is a metonym for the way a person walks, which in turn is a metaphor for the way a person decides how to live his life. Alternate translation: "keep his faithful people from making foolish decisions" or "enable his faithful people to make wise decisions" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-metaphor]])
This polite way of saying that Yahweh will kill the wicked can be stated in active form. Alternate translation: "Yahweh will put the wicked to silence in darkness" or "Yahweh will put the wicked in the dark and silent world of the dead" (See: [[rc://en/ta/man/translate/figs-euphemism]])
The words "be put to silence" are an idiom for "be made silent." This can be stated in active form. Alternate translation: "Yahweh will make them silent" (See: [[rc://en/ta/man/translate/figs-idiom]] and [[rc://en/ta/man/translate/figs-activepassive]])