A little background information is helpful before answering the question, what is the Nazirite vow?  The Hebrew word translated Nazirite is nazir and means “separated, separate from, consecrated or untrimmed (vine)”.  The Hebrew words nazar and nezer come from nazir; they mean separate and separation respectively.

The instructions regarding the Nazirite vow are found in Numbers 6. 

Num 6:2  “Speak to the children of Israel, and say to them: ‘When either a man or woman consecrates an offering to take the vow of a Nazirite [nazir], to separate [nazar] himself to the LORD,

A man or a woman could take the vow.  It was mentioned in the beginning paragraph that nazir can be translated “separate from”. An example is Genesis 49:26.

Gen 49:26  The blessings of your father Have excelled the blessings of my ancestors, Up to the utmost bound of the everlasting hills. They shall be on the head of Joseph, And on the crown of the head of him who was separate from [nazir] his brothers.

The Nazirite vow is a vow of separation to the Lord.

There were three basic rules to the vow.

(1) The individual was not to eat or drink any product of grapes. 

Num 6:3  he shall separate [nazar] himself from wine and similar drink; he shall drink neither vinegar made from wine nor vinegar made from similar drink; neither shall he drink any grape juice, nor eat fresh grapes or raisins.
Num 6:4  All the days of his separation [nezer] he shall eat nothing that is produced by the grapevine, from seed to skin.

It was mentioned in the beginning paragraph that nazir can be translated “untended vine”. An example is Leviticus 25:5.

Lev 25:5  What grows of its own accord of your harvest you shall not reap, nor gather the grapes of your untended vine [nazir], for it is a year of rest for the land.

The meaning “untended vine” is interesting because abstinence from grape products is figuratively leaving the vine untended.  Thus, Nazirite means “separate” and “untended vine”, and the Nazirite vow is a vow of separation from vine products.

What does abstinence from grape products symbolise?  Grapes are mostly used for wine and so abstinence from grape products pictures keeping one’s mind clear.  You cannot serve God while inebriated.  Priests could not serve God and drink wine.

Lev 10:9  “Do not drink wine or intoxicating drink, you, nor your sons with you, when you go into the tabernacle of meeting, lest you die. It shall be a statute forever throughout your generations,

(2) The individual was not to cut or shave his hair. 

Num 6:5  ‘All the days of the vow of his separation [nezer] no razor shall come upon his head; until the days are fulfilled for which he separated [nazar] himself to the LORD, he shall be holy. Then he shall let the locks of the hair of his head grow.

What does not cutting one’s hair symbolise?  Looking at the example of Samson can help.  Samson was a Nazirite from birth.  An angel appeared to Samson’s mother before he was conceived and pronounced.

Jdg 13:5  For behold, you shall conceive and bear a son. And no razor shall come upon his head, for the child shall be a Nazirite to God from the womb; and he shall begin to deliver Israel out of the hand of the Philistines.”

Samson attributed his strength to not having his hair cut.  Obviously Samson’s strength came from God not his hair, but nevertheless God took Samson’s strength away when he cut his hair.

Jdg 16:17  that he told her all his heart, and said to her, “No razor has ever come upon my head, for I have been a Nazirite to God from my mother’s womb. If I am shaven, then my strength will leave me, and I shall become weak, and be like any other man.”

From the example of Samson, we can see that not cutting one’s hair thus symbolises physical strength and dedicating all one’s strength to God.

(3) The individual was not to go near a dead body. 

Numbers 6:9-21 give instructions on what to do if the individual did come near a dead body.  He had to shave his head and make various offerings.

Num 6:6  All the days that he separates himself to the LORD he shall not go near a dead body.
Num 6:7  He shall not make himself unclean even for his father or his mother, for his brother or his sister, when they die, because his separation to God is on his head.
Num 6:8  All the days of his separation he shall be holy to the LORD.

What does not going near a corpse symbolise?  Priests could not go near a corpse.  Priests could go near their dead close relatives, but the high priest could not.  If they did they became defiled or unclean.

Lev 21:1  And the LORD said to Moses, “Speak to the priests, the sons of Aaron, and say to them: ‘None shall defile himself for the dead among his people,
Lev 21:2  except for his relatives who are nearest to him: his mother, his father, his son, his daughter, and his brother;

Lev 21:10  ‘He who is the high priest among his brethren, on whose head the anointing oil was poured and who is consecrated to wear the garments, shall not uncover his head nor tear his clothes;
Lev 21:11  nor shall he go near any dead body, nor defile himself for his father or his mother;

The rule for the Nazirite vow was like the rule for the High Priest.  Not going near a corpse symbolises keeping oneself pure or clean. 

The Nazirite vow was a commitment to separate oneself to God, and as we have seen there were three rules which have symbolic significance.

Does the Nazirite vow also symbolise the great commandment?

Mat 22:37  Jesus said to him, ‘YOU SHALL LOVE THE LORD YOUR GOD WITH ALL YOUR HEART, WITH ALL YOUR SOUL, AND WITH ALL YOUR MIND.’
Mat 22:38  This is the first and great commandment.

Is loving God with all your heart (strength) symbolised by not cutting hair?

Is loving God with all your soul (Greek, psuche – life) symbolised by not going near a corpse?

Is loving God with all your mind symbolised by abstinence from grape products?