To better understand the spiritual significance of the hair and shaving one’s head let us recall that in Lev 21:5 it was unlawful for the priests, who were always in the presence of God, to make their heads bald. We should also recall that in Leviticus one would shave himself as part of the process of being cleansed from various leprous types of infections, cf. Lev 13:29-37, 14:1-9, which perhaps held some spiritual significance as a symbol of putting off the old so as to make a new beginning. Similarly, in Dt 21:12 a foreign woman taken as a captive from Israel’s enemies was to shave her head and trim her nails before she could become an Israelite’s wife. And then there is the law of the Nazirite:
When a man or woman makes a special vow, the vow of a Nazirite, to dedicate himself to the LORD, he shall abstain from wine and strong drink (for he is to be filled with the Spirit of God rather than drunkenness and the spirit of this world; indeed…) he shall drink no vinegar, whether made from wine or strong drink, neither shall he drink any grape juice, nor eat fresh or dried grapes. All the days of his separation he shall not eat anything that is produced by the grape vine, from the seeds even to the skin (for among those dedicated to God there must not even be a hint of impurity, cf. Eph 5:3).
All the days of his vow of separation no razor shall pass over his head. He shall be holy until the days are fulfilled for which he separated himself to the LORD; he shall let the locks of hair on his head grow long. (The hair is what glorifies the physical head, as a type of the righteousness that glorifies the spiritual head who is Christ. Thus the hair is a symbol of the Nazirite’s righteous separation to God.)
All the days of his separation to the LORD he shall not go near to a (physically) dead person (as a type of the separation to be maintained from the spiritually dead). He shall not make himself unclean for his father or for his mother, for his brother or for his sister, when they die (cf. Mt 10:37), because his separation to God is on his head. All the days of his separation he is holy to the LORD. [“Come out from their midst and be separate,” says the Lord. “And do not touch what is unclean…”, 2 Cor 6:17.]
But if a man dies very suddenly beside him and he defiles his dedicated head (of hair), then he shall shave his head on the day when he becomes clean; he shall shave it on the seventh day. Then on the eighth day he shall bring two turtledoves or two young pigeons to the priest, to the doorway of the tent of meeting. And the priest shall offer one for a sin offering and the other for a burnt offering, and make atonement for him concerning his sin because of the dead person. And that same day he shall consecrate his head, and shall dedicate to the LORD his days as a Nazirite, and shall bring a male lamb a year old for a guilt offering; but the former days shall be void because his separation was defiled.
Now this is the law of the Nazirite when the days of his separation are fulfilled, he shall bring the offering to the doorway of the tent of meeting. And he shall present his offering to the LORD: one male lamb a year old without defect for a burnt offering and one ewe-lamb a year old without defect for a sin offering and one ram without defect for a peace offering, and a basket of unleavened cakes of fine flour (as a type of the peaceful fruit of righteousness that one dedicated to God must bear) mixed with oil (of the Spirit) and unleavened wafers spread with oil, along with their grain offering and their libations. Then the priest shall present them before the LORD and shall offer his sin offering and his burnt offering. He shall also offer the ram for a sacrifice of peace offerings to the LORD, together with the basket of unleavened cakes; the priest shall likewise offer its grain offering and its libation. The Nazirite shall then shave his dedicated head (of hair) at the doorway of the tent of meeting, and take the dedicated hair of his head and put it on the fire which is under the sacrifice of peace offerings. (Since the hair is the glory of the head, the Nazirite must give the glory to God). And the priest shall take the ram’s shoulder when it has been boiled, and one unleavened cake out of the basket, and one unleavened wafer, and shall put them on the hands of the Nazirite after he has shaved his dedicated (hair). Then the priest shall wave them for a wave offering before the LORD. It is holy for the priest, together with the breast offered by waving and the thigh offered by lifting up; and afterward the Nazirite may drink wine.
This is the law of the Nazirite who vows his offering to the LORD according to his separation, in addition to what else he can afford; according to his vow which he takes, so he shall do according to the law of his separation.
Numbers 6:1-21
And it came about when Delilah pressed Samson daily with her words and urged him, that his soul was annoyed to death. So he told her all that was in his heart and said to her, “A razor has never come on my head, for I have been a Nazirite to God from my mother’s womb. If I am shaved, then my strength will leave me and I shall become weak and be like any other man.“…And she made him sleep on her knees, and called for a man and had him shave off the seven locks of his head. Then she began to afflict him, and his strength left him. And she said, “The Philistines are upon you, Samson!” And he awoke from his sleep and said, “I will go out as at other times and shake myself free.” But he did not know that the LORD had departed from him….
Judges 16:16-17,19-20
Again the LORD spoke to Moses, saying, “Take the Levites from among the sons of Israel and cleanse them. And thus you shall do to them, for their cleansing: sprinkle purifying water (lit. water of sin) on them, and let them use a razor over their whole body, and wash their clothes, and they shall be clean.
Numbers 8:5-7
Then (after hearing of the calamities that had befallen him) Job arose and tore his robe and shaved his head, and he fell to the ground and worshiped.
Job 1:20
In that day the Lord will shave with a razor, hired from regions beyond the Euphrates (that is, with the king of Assyria), the head and the hair of the legs; and it will also remove the beard. (I.e., the king of Assyria will humble them and remove all their glory.)
Isaiah 7:20
Therefore in that day the Lord GOD of hosts, called you to weeping, to wailing, to shaving the head (i.e., removing one’s glory as an act of humiliation before the Lord), and to wearing sackcloth. Instead, there is gaiety and gladness, killing of cattle and slaughtering of sheep, eating of meat and drinking of wine: Let us eat and drink, for tomorrow we may die.”
Isaiah 22:12-13
Notice that as the hair represents one’s glory, that to shave one’s hair is to afflict and humble oneself as a symbol of great humiliation or mourning.
Do not enter a house of mourning, or go to lament or to console them; for I have withdrawn My peace from this people….Both great men and small will die in this land; they will not be buried, they will not be lamented, nor will anyone gash himself or shave his head for them.
Jeremiah 16:5-6
Now it happened on the next day after the killing of Gedaliah, when no one knew about it, that eighty men came from Shechem, from Shiloh, and from Samaria (where Israel had prostituted themselves) with their beards shaved off and their clothes torn and their bodies gashed, having grain offerings and incense in their hands to bring to the house of the LORD.
Jeremiah 41:4-5
For every head is bald and every beard cut short; there are gashes on all the hands and sackcloth on the loins.
Jeremiah 48:37
As for you son of Man, take a sharp sword; take and use it as a barber’s razor on your head and beard. Then take scales for weighing and divide the hair. One third you shall burn in the fire at the center of the city, when the days of the siege are completed. Then you shall take one third and strike it with the sword all around the city, and one third you shall scatter to the wind; and I will unsheathe a sword behind them. Take also a few in number from them and bind them in the edges of your robes. And take again some of them and throw them into the fire, and burn them in the fire; from it a fire will spread to all the house of Israel….One third of you will die by plague or be consumed by famine among you, one third will fall by the sword around you and one third I will scatter to every wind, and I will unsheathe a sword behind them.
Ezekiel 5:1-4,12
And all who handle the oar, the sailors, and all the pilots of the sea will come down from their ships; they will stand on the land, and they will make their voice heard over you and will cry bitterly. They will cast dust on their heads, they will wallow in ashes. Also they will make themselves bald for you and gird themselves with sackcloth; and they will weep for you in bitterness of soul with bitter mourning.
Ezekiel 27:29-31
Son of man, Nebuchadnezzar king of Babylon made his army labor hard against Tyre; every head was made bald, and every shoulder was rubbed bare. But he and his army had no wages from Tyre for the labor that he had performed against it.
Ezekiel 29:18
But the Levitical priests, the sons of Zadok, who kept charge of My sanctuary when the sons of Israel went astray shall stand before Me to offer Me the fat and the blood….They shall not shave their heads, yet they shall not let their locks grow long; they shall only trim the hair of their heads.
Ezekiel 44:15,20
Make yourself bald and cut off your hair, because of the children of your delight; extend your baldness like the eagle, for they will go from you into exile.
Micah 1:16