Adam Clarke on 1 Kings 21:27

He rent his clothes - He was penetrated with sorrow, and that evidently unfeigned.

Put sackcloth upon his flesh - He humbled himself before God and man.

And fasted - He afflicted his body for his soul's benefit.

Lay in sackcloth - Gave the fullest proof that his repentance was real.

And went softly - Walked barefooted; so the Chaldee, Syriac, and Arabic. The Vulgate has demisso capite, "with his head hanging down." Houbigant translates went groaning. Jarchi says that the word אט at, used here, signifies to be unshod. This is its most likely sense. All these things prove that Ahab's repentance was genuine; and God's approbation of it puts it out of doubt. The slow and measured pace which always accompanies deep and reflective sorrow is also alluded to by Aeschylus, where the Chorus are thus shortly addressed on the defeat of Xerxes. - Aesch. Pers. 1073. Γοασθ' ἁβροβαται "With light and noiseless step lament."