TT #281 · Parshas Tazria · Aliyah 7 · Passuk 52
English: undefined
Torah Temimah cites Yevamos 103b for the minimum cloth patch that can transmit impurity.
E-Daf — Yevamos 103b · Shas.org · Sefaria — Yevamos 103b, source text and translation
English: A cloth patch measuring three fingerbreadths by three fingerbreadths can transmit impurity even though it is smaller than an olive in volume: if most of it enters a pure house, it renders the house impure.
Textual derivation
A cloth patch measuring three fingerbreadths by three fingerbreadths can qualify under the relevant rule even when it is smaller than an olive in volume.