It was narrated that 'Aishah said:
"The Messenger of Allah (ﷺ) used to put his mouth on the place where I had drunk from, and he would drink from what was leftover by me, while I was menstruating." (ES)
English reference (ES): Vol. 1, Book 1, Hadith 281 (ES)
Arabic reference (ES): Book 1, Hadith 282 (ES)