Bhagavad Gita · Sankhya YogaChapter 2, Shloka 40 (2.40)

Two assurances.

1. No abhikrama-nāśa — effort begun is not lost. Shankaracharya: in work like farming, if you begin and leave it half done, everything is wasted; here it is not so. Ramanuja: even action that was begun, left incomplete, broken off midway, is not fruitless.
2. No pratyavāya — no adverse result. In Vedic ritual, a mistake in procedure was believed to bring an adverse result (a fault); in karma-yoga — according to Shankara — there is no adverse effect, as there can be with medical treatment. Ramanuja: even if the action begun is broken off, there is no pratyavaya (fault).

"Svalpam apy asya dharmasya" — even a little. Perhaps one of the most reassuring sentences in the Gita. Even if it cannot be complete — even a little action done in the right spirit saves one "mahato bhayāt" — from great fear. Ramanuja: saṃsāra-bhayāt — from the fear of samsara. He links this to 6.40 — "neither here nor there is he destroyed".