Bless the Lord - The psalm began Psalms 103:1-2 with an exhortation to “bless the Lord.” That exhortation was, however, then addressed by the psalmist to his own soul, and was especially founded on the benefits which he had himself received. The psalm closes also with an exhortation to “bless the Lord,” yet on a much wider scale. The psalmist feels that there is not only occasion for him to do it, but that the reason for it extends to the whole universe. The meaning is, that God is worthy of universal praise; and all ranks of beings - all worlds - should join in that praise. Man, feeble, frail, dying, could not come up to the fullness of the praise required. Praise such as was appropriate to God - such as his perfections and works deserved - demanded loftier powers than those of man; the loftiest powers in the universe.
Ye his angels - All beings higher than man; beings around and before his throne.
That excel in strength - Margin, as in Hebrew, “mighty in strength,” and therefore more “able” to offer adequate praise.
That do his commandments - Who perfectly obey his law, and who, therefore, can render more acceptable praise than can ever come from human lips.
Hearkening unto the voice of his word - Who always listen to his voice; who never are disobedient; and who can, therefore, approach him as holy beings, and more appropriately worship him.