Riyad as-Salihin, Book 3, Hadith 764 (In-Book) ⓘ

Umm Thabit Kabshah (May Allah be pleased with her), daughter of Thabit (May Allah be pleased with him) and the sister of Hassan bin Thabit, the Prophet's poet) reported: Messenger of Allah visited me and drank some water from a hanging water-skin while he was in a standing posture. So, I stood up and cut off the mouth (of that water-skin). An-Nawawi said that the reason why she did this was to keep to receive benediction that part of the water-skin which the lips of Messenger of Allah touched.[At- Tirmidhi].

وعن أم ثابت كبشة بنت ثابت أخت حسان بن ثابت رضى الله عنه وعنها قالت‏:‏ دخل على رسول الله صلى الله عليه وسلم، فشرب من في قربة معلقة قائماً، فقمت إلى فيها فقطعته‏.‏ ‏‏.‏