וְכָל־הַנֹּגֵ֖עַ בְּמִשְׁכָּבָ֑הּ יְכַבֵּ֧ס בְּגָדָ֛יו וְרָחַ֥ץ בַּמַּ֖יִם וְטָמֵ֥א עַד־הָעָֽרֶב׃
И всякий, кто прикоснется к ее постели, должен выстирать свою одежду, вымыться в воде и быть нечистым до вечера.
Sifra
11) (Vayikra 15:20) "And all that she lies upon in her niddah state shall be unclean, and all that she sits upon shall be unclean": I might think that she confers tumah upon a mishkav that is not distinctive for reclining upon and upon a moshav (a seat) that is not distinctive for sitting upon. It is, therefore, written (Vayikra 15:21) "And whoever touches her (distinctive) mishkav shall wash his clothes."