It is narrated from Sayyidah Maymunah (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) used to touch any of his wives while she was menstruating, if she had on a waist-wrapper reaching the middle of her thighs or her knees, and she had it tied around her.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20389