Reference for Kelim 24:5

שְׁלֹשָׁה תַרְבּוּסִין הֵן. שֶׁל סַפָּרִין, טָמֵא מִדְרָס. שֶׁאוֹכְלִין עָלָיו, טָמֵא טְמֵא מֵת. וְשֶׁל זֵיתִים, טָהוֹר מִכְּלוּם:

There are three types of leather covers: one used by barbers [for their customers to sit upon] is susceptible to <i>midras</i> impurity; one which people eat upon is susceptible to corpse impurity; and one which is for [spreading out] olives is pure from all [types of impurities].

Jastrow