Then God turned. Rather, “But God turned.” Israel had turned from Moses, God’s representative, and now God turns from them (cf. Joshua 24:20). Men have come to a fearful state when God must give them up (see on Hosea 4:17; 5:6). It is this appalling condition that Paul describes in Rom. 1:24, 26, 28.
To worship. Gr. latreuo, “to serve for hire,” and, by extension, “to render religious service,” “to worship.”
The host of heaven. See on Deut. 4:19; Zeph. 1:5. Israel had been warned against such worship as being a form of idolatry (Deut. 4:19; 17:3). But both historians (2 Kings 17:16; 23:5; 2 Chron. 33:3, 5) and prophets (Jer. 8:2; 19:3; Zeph. 1:5) record that the warning was in vain. This worship of the heavenly bodies is known as Sabaism. It is alluded to in such NT references to astrology as this.
The book of the prophets. That is, the prophets of the OT (see on Luke 24:44). The Jews generally considered the writings of the twelve so-called minor prophets one book. Stephen, following the general custom, does not identify the author of his quotation.
Have ye offered? Rather, with the emphasis of the Greek word order, “Did ye offer unto me slain beasts and sacrifices forty years in the wilderness, O house of Israel?” The quotation is, with minor changes, from the LXX of Amos 5:25, 26. In terms of historical fact, the question is to be answered in the affirmative, for sacrifices were offered to God during the wilderness wanderings. But spiritually, the answer is in the negative, for many of the people, though making the sacrifices, were also worshipping false gods, and the Lord rejected their divided worship.