And at that time I will search Jerusalem with lamps and punish the men settled in complacency, who say to themselves, ‘The LORD will do nothing, either good or bad.’
The Prophet addresses here generally the despisers of God, who were become hardened in their wickedness. But before he openly names them, he says that the visitation would be such, that God would search every corner, so that no place would remain unexplored. For to visit with candles, or to search with candles, is so to examine all hidden places or coverts, that nothing may escape.
Notice is here given to Judah and Jerusalem that God is coming forth against them, and will be with them shortly; his presence, as a just avenger, his day, the day of his judgment and his wrath, are not far off, Zep 1:7.
Commenting on Zephaniah 1:7-13
And it shall come to pass at that time, [that] I will search Jerusalem with candles To find out the sins of the inhabitants of it, and the authors of them, and punish them for them, however hid and concealed from the eyes of others, or thought to be: this must be understood consistent with the omniscience of God, who knows all persons and things...