This is the word of the LORD that came to Zephaniah son of Cushi, the son of Gedaliah, the son of Amariah, the son of Hezekiah, in the days of Josiah son of Amon king of Judah:
Zephaniah first mentions the time in which he prophesied; it was under the king Josiah. The reason why he puts down the name of his father Amon does not appear to me. The Prophet would not, as a mark of honor, have made public a descent that was disgraceful and infamous. Amon was the son of Manasseh, an impious and wicked king; and he was nothing better than his father.
That Zephaniah descended from King Hezekiah gave him standing to reprove the king's own children. When magistrates and ministers work together in reformation, removing idolatry as both did under Josiah, the work prospers; when they do not, corruption returns even in a godly reign.
AI summary
Commenting on Zephaniah 1:1-6
The word of the Lord which came unto Zephaniah the son of Cushi This is the title of the book, which expresses the subject matter of it, the word of the Lord; the word of prophecy from the Lord, as the Targum; and shows the divine authority of it; that it was not of himself, nor from any man, but was of God; as well...