Give unto the Lord - Ascribe unto the Lord - to Yahweh. This is extracted literally from 1 Chronicles 16:28.
O ye kindreds of the people - Hebrew, “Families” of the people: people, as united by family ties. The idea is that of worship not merely as individuals, nor as a mere “aggregate” of individuals united by no common bonds, but as those united by strong ties; bound by blood and affection; constituted into communities. It is a call on such to worship God in their capacity as thus bound together; to come as families and to worship God. In other words, it is a call on families “as such” to acknowledge God. A family is a proper place where to honor God. When the same joy pervades all hearts in prosperity, and when all are alike made sorrowful in adversity, there is an evident fitness that all should unite in the same worship of God; and that, as in all other things they have common interests, sympathies, and affections, so they should have in religion - in the service of their Creator.
Give unto the Lord glory and strength - That is, Proclaim that these belong to God; or, worship him as a God of glory and power.