Riblah is (far) north of Judah (in Syria). Due to the military-political situation, Pharaoh Neco had his headquarters there. That ruler then ruled the areas between the Euphrates and Egypt. King Jehoahaz went to Riblah voluntarily or was summoned by Neco. There he was arrested. Possibly because Pharaoh Neco wanted to make clear that it is not the people of Judah (see 2 Kings 23:30) but he who determines who will be king. Or because Jehoahaz had an anti-Egypt attitude (which may have been the reason for the people to proclaim him king). Afterwards he was taken as a prisoner to Egypt and there he died. That he would die in exile in a foreign country was foretold by Jeremiah (see Jeremiah 22:12). A fine is imposed on the country—this is what conquerors did, for thus conquered nations were kept small, while the conqueror could use the money for increasing his power. Compared to an earlier fine (see 2 Kings 18:14), this fine is considerably less high. That may be because Judah was now more impoverished; and/or because Pharaoh Neco did not want to embitter the Judean people.
33 And Pharaoh Neco put him in bonds at Riblah in the land of Hamath, that he might not reign in Jerusalem, and laid on the land a tribute of a hundred talents of silver and a talent of gold.