It is narrated from Sayyidah Umm Salamah (may Allah be pleased with her); she said: My menstruation came upon me suddenly while I was with the Messenger of Allah (peace and blessings be upon him), so I slipped away quietly. He (peace and blessings be upon him) said: "O Umm Salamah, perhaps your menses have come?" I said: Yes. He (peace and blessings be upon him) said: "Then come back and lie down." She said: So I came back and lay down, and between me and him (peace and blessings be upon him) there was only a waist-wrapper that did not go beyond the knees.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20004