Amos 2:3

I will cut off the ruler from its midst,
and will kill all its princes with him,"

says the LORD.

3. the judge—the chief magistrate, the supreme source of justice. “King” not being used, it seems likely a change of government had before this time substituted for kings, supreme judges.

I will cut off the ruler (Hebrew: judge) from its midst, and I will slay all its princes (Hebrew: leaders) with him (rsv)/ I will kill the ruler of Moab and all the leaders of the land. The tev, with its prose restructuring, has combined I will cut off (rsv) and I will slay (rsv), which will need to be done in many other languages as well. In most translations also, the word “judge” should not be translated literally, since in most cultures the work of judging and of ruling is quite different. Ruler is the meaning here.* Where no general term like ruler is possible, some other more specific term may have to be used, but there is no clear indication as to the precise status of this ruler. From early times Moab had been a monarchy (Num 23.7; Judges 3.12ff; 2 Kgs 3.4ff; Jer 27.3; Mesha inscription 1.23), and the function of the ruler was certainly similar to that of a king or chief (mft: “monarch”; Smith-Goodspeed: “chieftain”).
All the leaders of the land will, of course, sometimes be better translated “all its leaders.”
Says the Lord. (rsv) See 1.5.

He shall know there is a judge that is higher than he. The king, the chief judge, and all the inferior judges and princes, shall be cut off together. If the people sometimes suffer for the sin of their princes, yet the princes themselves shall not escape, Jer. 48:47. Thus far is the judgment of Moab.

The judge; shophet, probably here a synonym for “king” (comp. Micah 5:1). It implies the chief magistrate, like the Carthaginian sufes, which is the same word. There is no ground for deducing, as Hitzig and Ewald do, from the use of this form that Moab had no king at this time. The country was conquered by the Chaldeans, and thenceforward sank into insignificance (Jer. 48; Ezek. 25:8–11).