John Gill, on Jer 51:42

And I will punish Bel in Babylon,.... The idol of the Babylonians, who had a temple in Babylon, where he was worshipped: the same is called Belus by Aelianus (g), Curtius (h), and Pausanias (i); perhaps the same Herodian (k) calls Belis, and says some take him to be Apollo; for more of him; see Gill on Isa 46:1; and See Gill on Jer 50:2; who was punished when his temple was demolished, and plundered of its wealth; this golden image of Belus was broke to pieces, and the gold of it carried away. The Targum is, "I will visit or punish them that worship Bel in Babylon:'' and I will bring forth out of his mouth that which he hath swallowed up; the rich offerings made to him when victories were obtained; all success being ascribed to him; and the spoils of conquered enemies, which were brought and laid up in his temple, particularly the vessels of the sanctuary at Jerusalem, which were deposited there; see Ch2 36:7; and which were restored by Cyrus, Ezr 1:7; which restoration of them greatly fulfilled this prophecy; and was a refunding of what was lodged with him, or a vomiting what he had swallowed up; compare with this the story of "Bel and the dragon": and the nations shall not flow together any more unto him; either to worship him, or bring their presents to him, to ingratiate themselves with the king of Babylon: yea, the wall of Babylon shall fall; which Bel was not able to defend; and therefore should be deserted by his worshippers. The Targum renders it in the plural, the walls of Babylon; of which; see Gill on Jer 51:58. Some think that not the wall of the city is here meant: but the temple of Bel, which was as a wall or fortress to the city; but now should fall, and be so no more; since it is not easy to give a reason why mention here should be made of the fall of the walls of the city; and seeing express mention is made of this afterwards. (g) Var. Hist. l. 13. c. 3. (h) Hist. l. 5. c. 1. (i) L. 1. sive Attica, p. 29. (k) Hist. l. 8. c. 7.