The first occurrence.
And these are the kings that reigned in the land of Edom, before there reigned any king over the children of Israel. Gen 36:31
The primitive root.
Strong’s H4427 מלך malak, a primitive root meaning, “to reign.” The 3-letter root is mem + lamed + kaph.
mem מ ,ם = the water, thus chaos, mighty, blood
lamed ל = the shepherd’s staff, thus teach, yoke, to, bind
kaph כ , ך = the open palm, thus bend, open, allow, tame
The story: The mighty (mem, but may also carry the meaning of a blood line) who use their authority (lamed) to bless (kaph).