Then he took his eldest son, that should have reigned in his stead,.... Not the eldest son of the king of Edom, whom the king of Moab had in his hands before, which made the king of Edom the more willing to join in this expedition for the recovery of his son, as Joseph Kimchi thinks; or whom he took now in his sally out upon him, as Moses Kimchi and Ben Gersom, proceeding upon a mistaken sense of Am 2:1 for the king of Edom could have no son that had a right, or was designed to succeed him, since he was but a deputy king himself; and besides, the sacrificing of him was not the way to cause the kings to raise the siege, but rather to provoke them to press it the more closely: it was the king of Moab that took his son and heir to the crown,and offered him for a burnt offering upon the wall; that it might be seen by the camp of Israel, and move their compassion; or rather this was done as a religious action, to appease the deity by an human sacrifice so dear and precious, to give success, and cause the enemy to break up the siege; and was either offered to the true God, the God of Israel, in imitation of Abraham, as some Jewish writers fancy , or to his idol Chemosh, the sun; and Jarchi observes, out of an exposition of theirs, that "vau" is wanting in the word for wall, and so may be interpreted of the sun, towards which this burnt offering was offered; and it is observed, from various Heathen authors, that it was usual with the Heathens, when in calamity and distress, to offer up to their gods what was most dear and valuable to them; and particularly the Phoenicians , and from them the Carthaginians had this custom, who at one time offered up two hundred sons of their nobility, to appease their gods :and there was great indignation against Israel; not of the king of Edom against them, for not rescuing his son, or because they were the means of this disaster which befell him; but of the king of Moab, who was quite desperate, and determined to hold out the siege to the utmost extremity: and they departed, and returned to their own land; the three kings, the one to Edom, the other to Israel, and the third to Judah; when they saw the Moabites would sell their lives so dear, and hold out to the last man, they thought fit to break up the siege; and perhaps were greatly affected with the barbarous shocking sight they had seen, and might fear, should they stay, something else of the like kind would be done.
T. Bab. Sanhedrin, fol. 39. 2. Pesikta in Abarbinel in loc. Vid. Euseb. Evangel. Praepar. l. 1. c. 10. p. 40. l. 4. c. 16. p. 156. Porphyr. de Abstinentia, l. 2. sect. 56. Vid. Aelian. Var. Hist. l. 12.
c. 28. Diodor. Sicul. Bibliothec. l. 20. p. 756.