'Abstinence' in the Bible
‘All the time of the vow of his separation no razor shall be used on his head. Until the time of his separation to the Lord is completed, he shall be holy, and shall let the hair of his head grow long.
He shall not make himself [ceremonially] unclean for his father, mother, brother, or sister, when they die, because [the responsibility for] his separation to God is on his head.
All the time of his separation he is holy to the Lord.
‘Now this is the law of the Nazirite when the days of his separation and dedication are fulfilled: he shall bring the offering to the doorway of the Tent of Meeting (tabernacle).
The priest shall take the boiled shoulder of the ram, and one unleavened [ring-shaped] loaf out of the basket, and one unleavened flat cake and shall put them on the hands of the Nazirite after he has shaved his dedicated hair.
“This is the law for the Nazirite who vows his offering to the Lord for his separation, besides what else he is able to afford, according to the vow which he has vowed; so shall he do according to the law for his separation and abstinence [as a Nazirite].”
But after long abstinence Paul stood forth in the midst of them, and said, Sirs, ye should have hearkened unto me, and not have loosed from Crete, and to have gained this harm and loss.
They forbid marriage and demand abstinence from foods that God created to be received with gratitude by those who believe and know the truth.