Numbers 6:2-4

2“Speak to Bnei-Yisrael and say to them: Any man or woman who desires to vow a Nazirite vow to be separate for Adonai,

3is to abstain from wine and any other fermented drink. He is not to drink any vinegar made from wine or any fermented drink, or any grape juice, or eat grapes or raisins.

4“All during his days as a Nazirite he is not to eat anything from the grapevine—even the seeds or skins.