Parashas Metzora · Passuk 15:05
Chabad.org — English translation + Rashi
Torah Temima points to Toras Kohanim.
English: “And a man who touches” — this teaches that [only] at the time of his contact does he convey impurity to garments; once he has separated, he no longer conveys impurity to garments.
Impurity of clothes only during contact
Chazal limit the clothes-impurity of one who touches the zav’s bed to the moment of contact; after separation, further clothes contact is not affected by that prior touch alone.