Parashas Metzora · Passuk 15:24
Chabad.org — English translation + Rashi
Torah Temima points to Toras Kohanim.
English: “And every bed” — what does this teach? Scripture transferred him from severe impurity to lighter impurity, to say that he conveys impurity only to food and liquids [not full midras of people and clothes in the same way].
Downgrade of his midras effect
Chazal limit the midras of the man who lay with a niddah: his bed conveys a lighter impurity (foods and liquids) rather than the full midras of the niddah herself.