- Is cutting vegetables treated as sin according to Sanatana dharma?
- If so, how can one purify oneself of the sin?
- Is there some sort of prayer or respect one needs to offer the vegetables before we cut them?
- Similarly, is there some sort of prayer or respect one needs to offer food before we consume food in general?
No, cutting vegetables is not a sin as eating them is allowed in the primary Hindu book of law:
What is sthavara (immovable i.e. vegetables, plants, etc.) is the food of jangama (movable i.e. animals) [Manu Smruti - 5.29]
Because it is not a sin, there are no prescribed purifications present for it in the scriptures as far as I know.
But because it is a karma nevertheless, one can mentally show some respect to the vegetable and ask for forgiveness if one would like as done by saints and sadhus.
There are no fixed prayers for it, but food is mentally offered to the God you like. When I was a child I was told to use a mantra to chant before taking food and later on I found that verse to be present in Gita:
brahmārpaṇaṁ brahma havir brahmāgnau brahmaṇā hutam
brahmaiva tena gantavyaṁ brahma-karma-samādhinā [BG - 4.24]
Yes, taking life of any lifeform is a sin, but in order to live we must eat something. As Krishna says in the Gita:
BG 3. 14-15: From food all creatures are born... and
BG 6. 31: ...worships Me dwelling in all beings...
BG 13. 28: Because he sees the Lord present alike everywhere, he does not injure Self by self... and
BG 18. 48: ...for all undertakings are beset with imperfections, as fire with smoke.
It is a very minor sin compared to the sin of destroying the health of a human body which has the greatest manifestation of the atman of any living creature. Better to live on the flesh of swine and chant the name of the Lord than to be a vegetarian and a rogue.
If the only karma you are accountable for in this life is cutting vegetables, you are a great saint. Even Ramakrishna Parmahamsa would kill lice he found in his bedding.
See everything as God. See the Gita quotes in 1 above.
Different sects have different prayers. See the food as prasad from God. One good prayer to say beforehand is Gita 4.24:
brahmārpaṇaṁ brahma havir
brahmāgnau brahmaṇā hutam
brahmaiva tena gantavyaṁ