Albert Barnes Commentary Acts 12:8

"And the angel said unto him, Gird thyself, and bind on thy sandals. And he did so. And he saith unto him, Cast thy garment about thee, and follow me." — Acts 12:8 (ASV)

Gird yourself. When they slept, the outer garment was thrown off, and the girdle with which they bound their inner garment, or tunic, was loosened. He was directed now to gird up that inner garment as they usually wore it; that is, to dress himself, and prepare to follow him.

Bind on your sandals. Put on your sandals—prepared to walk. (See Barnes on Matthew 3:11).

Cast your garment about you. The outer garment, that was thrown loosely around the shoulders. It was nearly square, and was laid aside when they slept, or worked, or ran. The direction was, that he should dress himself in his usual apparel. (See Barnes on Matthew 5:38-42).