Matthew Poole and continuators on Zephaniah 1:5

5 And them that worship the host of heaven upon the house tops , and them that worship, and that swear by the LORD , and that swear by Malcham .

Those among the people that adhered to this Idolatry▪

The Sun, Moon, and Stars frequently in the Scripture called the host of Heaven.

Openly, as the manner of those Idolaters was, either because they thought those Deities they imagined to dwell in the body of those Stars better saw them, or were better pleased thus, or because these places were nearer Heaven. On the flat roofs of their houses they were used to have their Altars and Worship.

Or, to the Lord, (as the Heb bears) persons that mix Idol Worship, and the Worship of the true God; that devote themselves to God, and Baal, or Malcham

called Milcom, and Molech, and Moloch, Amos 5.26. probably 'twas their chief Idol, fancied to be King of Gods and Men.

Marginal references: 2 Kin. 23.12. Jer. 19.13.; Or, to the LORD.