佛說目連問戒律中五百輕重事經 2.3

2.3

問：「三衣事，浣要須捨不？」答：「須捨。若不捨犯捨墮。當施與人，還乃得更受。」

Question: "Regarding the three robes, is it necessary to relinquish them when washing them or not?"
Answer: "They must be relinquished. If not relinquished, it incurs a naiḥsargika-pāyattika. One should give them to someone, and only after receiving them back may one take them up again."