Sefer Chasidim Siman 896
Can copy this into an AI, or connect the whole library to your assistant. For deeper learning, you can directly use the original seforim, sites, and apps.
מי שנפל לו דיו ביום טוב או שום דבר לח על הספרים בפנים על הכתב אל ילחכנו בלשון ואל ירחצנו במים מפני שמוחק:
Medieval Jewish mysticism, translated by Sholom Alchanan Singer. Northbrook, Ill. Whitehall Co., 1971
If it happened that on a holiday (yom tov) ink or any other liquid fell on seforim so that it got on the place where text is written one should not lick it off with a tongue or wash it off with water because in doing so he performs erasing.