Musnad Ahmad 1153:361

Hassan narrated to us, he said: Ibn Lahi'ah narrated to us, he said: Huyayy ibn Abdullah narrated to us, that Abu Abd al-Rahman al-Hubuli narrated to him, from Aisha, the wife of the Prophet, may Allah bless him and grant him peace: "Menstruation came upon her during the night, while the Messenger of Allah, may Allah bless him and grant him peace, was praying. She signaled to the Messenger of Allah, may Allah bless him and grant him peace, with a garment that had blood on it. The Messenger of Allah, may Allah bless him and grant him peace, signaled to her while he was in prayer: 'Wash it.' So she washed the place of the blood. Then the Messenger of Allah, may Allah bless him and grant him peace, took that garment and prayed in it."