ציטירנדיקער פּירוש אויף ויקרא 15:7

For a person who touches a zav can defile garments, whereas garments that touch a zav cannot defile [other] garments. A person who has been in contact with a zav defiles clothing. This is explicit in Leviticus 15:7. However, clothing that come into contact with a zav has first degree impurity. This impure clothing will not subsequently convey impurity to other clothing, for clothing is susceptible to impurity only through contact with a father of impurity.