Not to erect a column in a public place of worship

This mitzvah forbids setting up a matzeivah — a single stone or pillar designated for worship. Although the forefathers once used such monuments to honor Hashem, the practice was later corrupted by idolaters and therefore became abhorrent. The Torah bans it entirely to distance Israel from idolatrous customs and to preserve the distinctiveness of proper worship.

Commentary & Classical Explanation:

• Rambam (Hilchot Avodat Kochavim 6:6): Even if one dedicates the pillar to Hashem, the act is forbidden because idolaters adopted it.
• Sefer HaChinuch (Mitzvah 429): The root is to reject foreign worship practices, ensuring Israel’s service of Hashem remains pure and distinct.
• Talmud (Avodah Zarah 52b): Explains that what was once beloved in the days of the Patriarchs later became despised because idolaters misused it.