It is narrated from Sayyiduna Abu Musa Ash'ari (may Allah be pleased with him), who reported that the Prophet (peace and blessings of Allah be upon him) was sitting in a garden on the edge of a well, with his feet dangling into the well.
Hadith Referenceالادب المفرد / كتاب / 1195
Hadith Gradingالألبانی:حسن صحيح
Hadith Takhrij«حسن صحيح : أخرجه أحمد : 19653 و النسائي فى الكبرىٰ : 8076 - و أنظر الحديث رقم : 1151»
Explanation & Benefits
Shaykh Maulana Usman Muneeb
Benefits and Issues: The explanation of this hadith has already been mentioned in the previous pages. From this, it is understood that if the place of sitting is such that it is easy to sit with the legs hanging down, then there is no harm in it, and it is not contrary to decorum.
Source: Fadlullah al-Ahad: Urdu Commentary on al-Adab al-Mufrad, Page: 1195