John Calvin Commentary Isaiah 47:12

"Stand now with thine enchantments, and with the multitude of thy sorceries, wherein thou hast labored from thy youth; if so be thou shalt be able to profit, if so be thou mayest prevail." — Isaiah 47:12 (ASV)

Stand now amidst thy divinations. The Prophet speaks as we are accustomed to speak to desperate men, on whom no warnings produce any good effect; “Do as you are accustomed to do; in the end you will be instructed by the event; you will know what good the augurs and soothsayers do for you.” By the word “stand” he alludes to the custom of the augurs, who remain unmoved in one place until some sign is seen. In like manner, the astrologers mark out their divisions in the heavens, even to the minutest points. If it is thought preferable to translate חברים (chabarim) diviners instead of divinations, I will not greatly object; for the meaning of the word is ambiguous.

If perhaps thou shalt prevail. As if he had said, “You will not be able, by the aid of your augurs, to mitigate the calamity which is about to overtake you.” He taunts their perverse confidence on this ground, that when they have made every attempt, no advantage will follow.