the Berasit Hebrew Dictionary

מצב

'mexeb' is essentially a rough, naturally shaped oblong stone “menhir” that someone has stood on end to form a monument. A menhir is defined as a “standing stone”¹⁾ that may have been “used as territorial markers, or elements of a complex ideological system, used as mnemonic systems for oral cultures”.²⁾

Jacob is narrated as performing exactly this act in Genesis 28:18. The same stone is then revisited throughout the chapter and again at a later date in chapter 31.

Jacob sets up two additional menhirs in Genesis35:14 and Genesis 35:20.

Each of these are part of a ceremony and are done specifically to commemorate a specific event.

Moses carries on this tradition when he erects 12 menhirs in Exodus 24:4.

Strangely though, Moses appears to outlaw the practice in Leviticus 26:1, but the law seems to go pretty much unregarded, as indicated in 1 Kings 14:23 and 2 Kings 17:10 which state that menhirs were erected “on every hill”.

Deuteronomy 16:22 links 'mexeb' with the qemim.