3. Sing unto him a new song. As the Psalmist afterwards treats of the mighty works of God, and particularly concerning the preservation of the Church, it is not wonderful that he exhorts the righteous to sing a new, that is, a rare and choice song. The more closely and diligently that believers consider the works of God, the more will they exert themselves in his praises. It is no common song, therefore, which he exhorts them to sing, but a song corresponding to the magnificence of the subject. This is also the meaning of the second clause, in which he urges them to sing loudly. In this sense, I understand the Hebrew word היתיב, heytib, although others refer it rather to the proper setting of the notes.