The abstract noun "justice" can be expressed as an adjective. Alternate translation: "do not understand what is just" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
Those who want to know Yahweh and please him are spoken of as if they are literally seeking to find Yahweh. (See: [[rc://en/ta/man/translate/figs-metaphor]])
The implied information is that those who seek Yahweh understand all about justice. Alternate translation: "completely understand what is just" (See: [[rc://en/ta/man/translate/figs-explicit]])