Reference for Niddah 65:23

יטמא ז' ימים מפסיק הענין הוי כלל ופרט המרוחקין זה מזה וכל כלל ופרט המרוחקין זה מזה אין דנין אותו בכלל ופרט

As she causes a couch or a seat to become unclean so as to impart uncleanness to a man and thereby also impart uncleanness to his clothes, so does he also cause his couch and seat to impart uncleanness to man and thereby impart uncleanness to his clothes, it was explicitly stated: And every bed whereon he lieth shall be unclean.<span class="x" onmousemove="('comment',' Lev, XV, 24. ');">¹⁸</span>

Jastrow