III, 4, 30
The Vedanta Sutras of Badarayana, Commentary by Sankara (SBE38), tr. by George Thibaut [1896] at sacred-texts.com
30. And this is said in Smriti also.
That in cases of need both he who knows and he who does not know may eat any food Smriti also states; compare e.g. 'He who being in danger of his life eats food from anywhere is stained by sin no more than the lotus leaf by water.'--On the other hand, many passages teach that unlawful food is to be avoided. 'Intoxicating liquor the Brâhmana must permanently forego;' 'Let them pour boiling spirits down the throat of the Brâhmana who drinks spirits;' 'Spirit-drinking worms grow in the
mouth of the spirit-drinking man, because he enjoys what is unlawful.'