Whoever sits on furniture on which the man with the discharge was sitting must wash his clothes and bathe with water, and he will be unclean until evening.
We have here the law concerning the ceremonial uncleanness that was contracted by running issues in men. It is called in the margin (Lev 15:2) the running of the reins: a very grievous and loathsome disease, which was, usually the effect and consequent of wantonness and uncleanness, and a dissolute course of life, filling men's bones with the sins of their youth, and leaving them...
Commenting on Leviticus 15:1-18
And he that sitteth on any thing whereon he sat that hath the issue,.... Shall be unclean, even though he does not touch it. Jarchi says, though there should be, as he adds, ten things or vessels one upon another, they all defile because of sitting, and so by lying: shall wash his clothes, and bathe himself in water, and be unclean until the even; as in the preceding case.
Lev 15:4-8 Every bed upon which he lay, and everything upon which he sat, was defiled in consequence; also every one who touched his bed (Lev 15:5), or sat upon it (Lev 15:6), or touched his flesh, i.e., his body (Lev 15:7), was unclean, and had to bathe himself and wash his clothes in consequence.
Commenting on Leviticus 15:4-8