(1.) His infinite perfections in himself. Here is one of his most glorious titles praised: he is the Lord of hosts, of their hosts, of all hosts; and one of his most glorious attributes, his holiness, without which his being the Lord of hosts (or, as it is in the parallel place, Rev. iv. 8, the Lord God Almighty) could not be so much as it is the matter of our joy and praise; for power, without purity to guide it, would be a terror to mankind. None of all the divine attributes is so celebrated in scripture as this is. God's power was spoken twice (Ps. lxii. 11), but his holiness thrice, Holy, holy, holy. This bespeaks, [1.] The zeal and fervency of the angels in praising God; they even want words to express themselves, and therefore repeat the same again. [2.] The particular pleasure they take in contemplating the holiness of God; this is a subject they love to dwell upon, to harp upon, and are loth to leave. [3.] The superlative excellency of God's holiness, above that of the purest creatures. He is holy, thrice holy, infinitely holy, originally, perfectly, and eternally so. [4.] It may refer to the three person in the Godhead, Holy Father, Holy Son, and Holy Spirit (for it follows, v. 8, Who will go for us?) or perhaps to that which was, and is, and is to come; for that title of God's honour is added to this song, Rev. iv. 8. Some make the angels here to applaud the equity of that sentence which God was now about to pronounce upon the Jewish nation. Herein he was, and is, and will be, holy; his ways are equal.