Albert Barnes Commentary Psalms 8:3

"When I consider thy heavens, the work of thy fingers, The moon and the stars, which thou hast ordained;" — Psalms 8:3 (ASV)

When I consider thy heavens - This means when I contemplate or look upon them. They are called his heavens because he made them, because he is their proprietor, and perhaps because they are his dwelling place.

The work of thy fingers - This means what your fingers have made. The fingers are the instruments by which we construct a piece of work, perhaps indicating skill rather than strength. This term is therefore used in reference to God, as it is by his skill that the heavens have been made.

The moon and the stars - This shows, as remarked above, that this psalm was probably composed at night, or that the train of thought was suggested by contemplating the starry worlds.

It is not unlikely that these thoughts occurred to the psalmist when meditating on the remarkable honor God had conferred on him, a feeble man (see the notes at Psalm 8:2). His thoughts were also directed to God's goodness as the heavens were contemplated in their silent grandeur.

Which thou hast ordained - This means prepared, fitted up, constituted, or appointed. He had fixed them in their appropriate spheres, and they now silently reveal his glory.