Deuteronomy 16:21-22 meaning

After asking the Israelite judges and officers to administer social justice with equity in the land of Canaan, Moses commanded that they were to not plant for yourself an Asherah of any kind of tree beside the altar of the LORD your God, which you shall make for yourself (v. 21).

The term Asherah could refer to a "sacred tree", a grove of trees, or even a wooden pole which stood at the worship places (Deuteronomy 7:5). It was also the name of the Canaanite fertility goddess Asherah.

To plant an Asherah tree/pole beside the altar of the LORD meant that it was going to be used in the worship of the LORD along with the altar. This was tantamount to associating pagan fertility symbols with the worship of the one true LORD. This was strictly prohibited, and if the priests failed to prevent this type of syncretism (mixing of religions), the judges and officials were tasked to enforce the law.

Not only were the Israelites not to worship the female goddess Asherah, they also were not allowed to set up for themselves a sacred pillar (v. 22). A sacred pillar refers to stones (either cut or uncut) that represented the male deity Baal (2 Kings 3:2; Deuteronomy 7:5). Baal was the chief Canaanite deity and was the god of fertility and reproduction. According to Canaanite myth, he had many consorts and was known as the storm god, the one who would bring rain to water the crops.

To set up these two pagan objects near the central sanctuary of the LORD would associate them with the worship of the LORD as well as validate their being worshipped. This was totally unacceptable because both the Asherah and the sacred pillar were objects which the LORD their God hates.

The people were forbidden from setting up these pagan objects anywhere in the Promised Land or associating them with the worship of the LORD. The priests were to enforce this restriction, but if they failed, it was up to the judges and officers mentioned in vv. 18 - 10 to do so.

By setting this provision in this location, Moses seems to underscore the fundamental incompatibility between paganism and God's self-governing system. This is likely because of the underlying goal of each system. Paganism fundamentally revolves around each person seeking to have their appetites and desires fulfilled at the expense of another. The deities' purpose is to provide a moral authority to human manipulation. For example, the extreme sexual exploitation listed in Leviticus 18 was, in many cases, an integral part of pagan worship. The same was true with human sacrifice. If burning children is considered holy, then any exploitation could be justified. God's way was to strictly forbid any such thing.

God's way is completely incompatible with a system of exploitation. Israel's God demanded the exact opposite. God's law required each Israelite to serve and love others. Exploitation of children and women was strictly forbidden. Exploitation of the poor, and those down on their luck was likewise forbidden. Each Israelite was so valuable in the eyes of God, that they were to receive the same exact justice as the most esteemed person in the land. Any mixing of pagan worship would erode God's system, and must not be tolerated. God made special mention of this so that the judges would be conscious of it. They would have a position of authority from which it would be possible to exploit others, but instead they were to strictly prohibit the inclusion of pagan worship and its accompanying system of exploitation.