Here John appears like Samson and Samuel, who, like John, took the nazirite vow (cf. Judges 13:4-5; I Samuel 1:11) and were consecrated to the Lord. Those who took this vow were regarded as prophets as long as they remained under the vow.
The word “nazirite” itself comes from the Hebrew word, nazir, meaning, “set apart as sacred, dedicated, vowed.” Even from the womb, then, John was dedicated to the service of the Lord.
This vow of the nazirite was given by the Lord through Moses:
When a man (or a woman) solemnly takes the nazirite vow to dedicate himself to the Lord, he shall abstain from wine and strong drink; he may neither drink wine vinegar, other vinegar, or any kind of grape juice, nor eat either fresh or dried grapes. As long as he is a nazirite he shall not eat anything of the produce of the vine, not even unripe grapes or grapeskins. While he is under the nazirite vow, no razor shall touch his hair. Until the period of his dedication to the Lord is over, he shall be sacred, and shall let the hair of his head grow freely. As long as he is dedicated to the Lord, he shall not enter where a dead person is. Not even for his father or mother, his sister or brother, should they die, may he become unclean, since his head bears his dedication to God. As long as he is a nazirite he is sacred to the Lord (Numbers 6:2-8).From his birth, then, we see that John was set apart for the Lord, to be the “voice of one crying out in the desert, ‘Prepare the way of the Lord’” (Isaiah 40:3).
There is more that we can learn of the Baptist if we consider not only what he did not drink, but also what he ate. Both Matthew and Mark tell us that John’s diet consisted of “locusts and wild honey” (Matthew 3:4; Mark 1:6).
Under the Old Covenant, locusts were among the insects that could be eaten (cf. Leviticus 11:22). By eating locusts, John remained faithful to the Law and also renounced worldly pleasures.
The locusts may also call to mind the eighth plague visited upon the Egyptians for their stubbornness to release the Hebrews (cf. Exodus 10:4-6). Peter Chrysologus tells us that “locusts intended for sinners worthy of chastisement are rightly considered to be food for repentance, so that bounding from the place of sin to the place of repentance the sinner may fly to heaven on the wings of forgiveness.”
Yet Origen suggests a further reason for John to eat locusts: “John ate locusts, suggesting that the people of God were being nourished by a word that traveled high aloft in the air and had not yet passed over the earth.” It was John the Baptist, after all, who said of this Word made flesh, “Behold the Lamb of God, who takes away the sin of the world” (John 1:29).
The reason that John ate locusts, then, is threefold: to remain faithful to the Law, to call the people to repentance, and to point out the coming of the “living bread that came down from heaven” (John 6:51).
But what of the honey that John also ate? It surely alludes back to the Promised Land, to the land “flowing with milk and honey” (Exodus 3:8). This land the Lord promised his people, but they lost it by disobeying his commands. Baruch says to the people:
And the evils and the curse which the Lord enjoined upon Moses, his servant, at the time he led our father forth from the land of Egypt to give us the land flowing with milk and honey, cling to us even today. For we did not heed the voice of the Lord, our God, in all the words of the prophets whom he sent us, but each of us went off after the devices of our own wicked hearts, served other gods, and did evil in the sight of the Lord, our God (Baruch 1:20-22).Simply through his diet, John the Baptist reminds the people of Israel of the promise of God given through Moses:
For the Lord, your God, is brining you into a good country, a land with streams of water, with springs and fountains welling up in the hills and valleys, a land of wheat and barley, of vines and fig trees and pomegranates, of olive trees and honey, a land where you can eat bread without stint and where you will lack nothing (Deuteronomy 8:7-9).But the eating of honey was not only for the Promised Land; together with curds, honey was the food prescribed the Prophet Isaiah for those who remain in Israel after the devastation of the exile (cf. Isaiah 7:22). Either way, honey is intimately connected with the promise of God.
John’s eating of the honey, then, reminds us of the promise of redemption given by God, a promise so near to fulfillment with the advent of the Baptizer. His eating of honey is also a call to heed well the words he preaches and to answer his call to repentance lest this promise be taken away at the coming of the one whose “winnowing fan in his hand to clear his threshing floor and to gather the wheat into his barn” (Luke 3:17).
When the prophet Ezekiel ate the scroll containing the message of doom, he found that it tasted “as sweet as honey in my mouth” (Ezekiel 3:3). It is this same message that the Psalmist sings is “sweeter also than honey or drippings from the comb” (Psalm 19:11). Elsewhere the Psalmist sings, “How sweet to my tongue is your promise, sweeter than honey to the touch” (Psalm 119:103). This honey also calls to mind the words of Psalm 81: “But Israel I would feed with the finest wheat, satisfy them with honey from the rock” (Psalm 81:17).
In his proverbs, King Solomon says, “If you eat honey, my son, because it is good, if virgin honey is sweet to your taste; such, you must know, is wisdom to your soul. If you find it, you will have a future, and your hope will not be cut off” (Proverbs 24:13-14). John surely has not been cut off, but has now entered that Promised Land where he “will lack nothing.”
We also know that John, together with his disciples, often fasted (cf. Mark 2:18). His fasting pointed to the reality that precisely because the promises of God were soon to be fulfilled in the Messiah, now is the time of repentance. For this reason he came preaching and baptizing.
 Peter Chrysologus, Sermons167.9.
 Origen, Fragment 41.