John Calvin Commentary Genesis 3:21

"And Jehovah God made for Adam and for his wife coats of skins, and clothed them." — Genesis 3:21 (ASV)

Unto Adam also, and to his wife, did the Lord God make, etc. Moses here, in a simple style, declares that the Lord had undertaken the task of making garments of skins for Adam and his wife. It is not truly proper to understand his words as if God had been a furrier or a servant sewing clothes.

Now, it is not believable that skins would have been presented to them by chance. Instead, since animals had previously been destined for their use, and being now driven by a new necessity, they put some to death to cover themselves with their skins. Having been divinely guided to adopt this plan, Moses therefore calls God the Author of it.

The reason the Lord clothed them with garments of skin appears to me to be this: garments made of this material would have a more degrading appearance than those made of linen or wool. God therefore intended that our first parents should, in such clothing, behold their own degradation—just as they had previously seen it in their nakedness—and thus be reminded of their sin. Meanwhile, it cannot be denied that He intended to offer us an example, by which He would accustom us to a frugal and inexpensive way of dressing.

And I wish those fond of luxury would reflect on this, who consider no ornament sufficiently attractive unless it exceeds in magnificence. Not that every kind of ornament is to be specifically condemned; but when excessive elegance and grandeur are carefully pursued, not only is that Master despised who intended clothing to be a sign of shame, but war is, in a sense, waged against nature.