In Isaiah 6:4 (“and the Temple filled up with smoke”), where no source of the smoke is specified, some exegetes have related it to God’s wrath, which is described as “smoking” (e.g., 2 Samuel 22:9; Deuteronomy 29:19). Others have suggested that the smoke emanates from the breath of the Seraphim. Shmuel D. Luzzato, a 19th-century Jewish commentator from Italy, suggests, however, that the Seraphim were offering incense while reciting the Trisagion (“Holy, Holy, Holy is the Lord of Hosts”). Whatever the source of the smoke, it is certainly reminiscent of the smoke of the Sinai theophany, as is the smoking furnace of Genesis 15:17.