“razor.” Israel had sinned against God for centuires, and Isaiah foretold that they would be “shaved” by the Assyrians in many ways. As it turned out, the Assyrians burned their cities and took the people and valuables captive to Assyria. Isaiah foretold that the extent of the destruction and disgrace would be almost unimaginable, and God personalized it by a picture of a person’s humiliation and defeat if an enemy captured a man (or woman) and shaved off the hair of the head and the genitals, and for a man, also the beard, all of which would be horribly disgraceful in that culture.
“feet.” Here “feet” it is an idiom, and used euphemistically for the genital organs. Isaiah 7:20 is a prophecy that when the Assyrians conquer Israel and take the people captive they will “shave the hair of the feet.” It is unfortunate that many versions say “shave the hair of the legs,” which misses the point entirely. Why would people shave the legs of their captives? The captives were led away “naked and barefoot” and “with buttocks bared” (Isa. 20:4). Isaiah was saying that not only will these captives be carried away naked with their buttocks exposed, but they would suffer the humiliation of having their pubic hair shaved by their Assyrian enemies. In Isaiah 47:2, which is a prophecy of when the Persians will carry the Babylonian women away captive, they will be stripped naked and their “thigh” will be uncovered, “thigh” being another sexual euphemism for the genitalia (see commentary on Isa. 47:2).
It was quite common that captives were stripped naked to humiliate them, and very common that the women were raped. The Hebrew word gala, which is used as “uncover” in a sexual sense (see Lev. 18 and 20 where “uncover” is used many times), is also used for “to be led captive” (2 Kings 17:11,28; 24:14; 25:11, etc.), perhaps because of the strong cultural connection between being taken captive and being stripped naked.
The “feet” are used idiomatically for the genital area in other verses as well. Ezekiel 16:25 says the woman “opened her feet” to everyone, referring to sexual intercourse. Another connection between the genital area and the feet can be seen in 2 Kings 18:27 and Isaiah 36:12 where the Hebrew phrase for urine is, “the water of the feet.”
Captives were also humiliated by shaving their beard or their hair. In 2 Samuel 10:4-5, the king of Ammon took the emissaries that had come from David and shaved off half their beards, and the men were so embarrassed that David had them stay away from Jerusalem until their beards had grown back. Isaiah 7:20 says that the Assyrians will be a razor that will shave the people of Judah; shave their heads, their beards, and their pubic hair. Jeremiah 2:16 personifies Israel and says that Egypt will shave his head.