Hadith: The Messenger of Allah (may Allah's peace and blessings be upon him) visited me and drank from the mouth of a hanging waterskin while he was standing. So, I got up and cut off its mouth

عن أم ثابتٍ كَبْشَةَ بنتِ ثابتٍ أُخْتِ حَسَّانَ بنِ ثابتٍ رضي الله عنهما ، قالت: دَخَلَ عَلَيَّ رسولُ اللهِ صلى الله عليه وسلم فَشَرِبَ مِنْ فِي قِرْبَةٍ مُعَلَّقَةٍ قائمًا، فقُمتُ إلى فِيها فَقَطَعْتُهُ.
[صحيح] - [رواه الترمذي وابن ماجه وأحمد]

Umm Thābit, Kabshah bint Thābit, sister of Hassān ibn Thābit, (may Allah be pleased with both of them) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) visited me and drank from the mouth of a hanging waterskin while he was standing. So, I got up and cut off its mouth.
[Authentic hadith] - [Narrated by Ibn Majah - Narrated by At-Termedhy - Narrated by Ahmad]

Explanation

Kabshah bint Thābit (may Allah be pleased with her) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) once visited her and drank from the mouth of a hanging waterskin while he was in a standing posture. He did that (although he forbade drinking while standing) because this was the only way he could drink from it while it was hanging. So Kabshah got up to the waterskin and cut off its mouth in order to preserve the spot where the Messenger of Allah (may Allah's peace and blessings be upon him) put his mouth to seek blessing from it and to protect it from being handled in a disrespectful manner (given that the Prophet's mouth had touched it).