This refers to the same people as "the house of the king of Judah." All of the kings of Judah were descendants of David. Alternate translation: "Descendants of David" (See: [[rc://en/ta/man/translate/figs-metonymy]])
The abstract noun "justice" can be stated as an action. Alternate translation: "Always treat the people whom you rule over fairly" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
Here Yahweh's punishment is spoken of as if it was a fire that would burn up those who did evil. Alternate translation: "I will punish and destroy you in my anger quickly and completely" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Jeremiah continues the simile of Yahweh's punishment as a fire that was so hot that no one could put it out with water. (See: [[rc://en/ta/man/translate/figs-metaphor]])