This question came up in the website Quora:

Deuteronomy 14:1 forbids the Israelites to "make baldness between their eyes for the dead." What does this refer to?

Here is the answer I gave (with amendments):

This commandment in the Torah does not prohibit the shaving of the head as such. The point is to forbid Israelites from hurting or doing damage to themselves when grieving the loss of a loved one.

The reference is to Canaanite mourning rituals which have been lost to time but which involved marring one’s appearance by self-cutting, self-mutilation, and anti-cosmetic shaving. Perhaps an archeological discovery may come along to shed light on what they were specifically and what was their rationale. While we have little direct evidence of the Cananite practices, we do have historical references such as those of the Greek Historian Herodotus many centuries after the Exodus who describes the behavior of the Scythians (a nomadic people from the steppes of Central Asia) on the death of their king: “They cut off a part of their ears, shave their heads, make cuts round their arms, tear their foreheads and noses, and pierce their left hands with arrows.” It seems likely that the Canaanites had similar extreme practices.

The Israelites were not absolutely barred from shaving the head, and in fact were required to do so upon the completion of certain vows (see Numbers 6:9,18) and for cleansing upon being healed from infectious skin diseases (“leprosy”; see Leviticus 14). But as a people holy to the LORD, the Israelites were to remember that their bodies also were to be kept holy, and idolatrous people may go to extremes to express their grief, the LORD’s people were to restrain their most extreme emotions and were prohibited from harming themselves in times of mourning. Deuteronomy 14:1 appears to expand the injunction originally laid on the priests (Leviticus 21:5) toward the Israelites in general.

This does not mean either that they were prohibited from showing extreme emotion (although the priests were restricted: see Exodus 10 as well as Leviticus 21). It simply means that they were to treat their own bodies as belonging not to themselves but to the LORD—a teaching echoed in the New Testament in 1 Corinthians 6:19-20—and it was not God’s will that they should do damage to themselves while in the throes of grief.