Charles Ellicott Commentary Isaiah 16:12

"And it shall come to pass, when Moab presenteth himself, when he wearieth himself upon the high place, and shall come to his sanctuary to pray, that he shall not prevail." — Isaiah 16:12 (ASV)

When it is seen ... —A better rendering is: When Moab appears (that is, as a worshipper), when he wearies himself on the high place (the scene of Chemosh-worship), though he enters into the sanctuary to pray, yet he will not prevail. The prophet draws a picture of the unavailing litanies which Moab, like the priests of Baal in 1 Kings 18:26, will offer to his gods.