וְכֹל֩ אֲשֶׁ֨ר תִּשְׁכַּ֥ב עָלָ֛יו בְּנִדָּתָ֖הּ יִטְמָ֑א וְכֹ֛ל אֲשֶׁר־תֵּשֵׁ֥ב עָלָ֖יו יִטְמָֽא׃
Segala sesuatu yang ditidurinya selama masa haidnya menjadi najis, dan segala sesuatu yang didudukinya menjadi najis.
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."
Sifra
12) (Vayikra 15:22) "And whoever touches any object that she sits upon shall wash his clothes": Just as below (i.e., Vayikra 15 verse 21, which elucidates verse 20), she confers tumah only upon a mishkav that is distinctive for lying upon and a moshav that is distinctive for sitting upon, here, too, she confers tumah only upon a mishkav that is distinctive for lying upon and a moshav that is distinctive for sitting upon.
Sifra
13) I might think that as far as conferring tumah is concerned, she confers tumah only upon a mishkav that is distinctive for lying upon and upon a moshav that is distinctive for sitting upon; but as far as becoming tamei is concerned, all kinds (of moshav and mishkav, even non-distinctive) are susceptible of this. For there are many things which become tamei and yet do not confer tumah (upon other things). It is, therefore written "upon it" - "upon it." "Upon it" is written in respect to becoming tamei (Vayikra 15 verse 22, lit., "that she sits upon it"), and "upon it" is written in respect to conferring tumah (Vayikra 15 verse 20). Just as with "upon it" in respect to conferring tumah, only a mishkav distinctive for lying upon and a mishkav distinctive for sitting upon confer tumah, so with "upon it" in respect to becoming tamei, only a mishkav distinctive for lying upon and a mishkav distinctive for sitting upon become tamei.