Is it recommended to choose soft ground for urination?
Chapter on Cleaning oneself (Istitabah) and Impurity (Hadath)
Al-Mughni
Book of Purification
Primary text
It is recommended to select soft ground for urination to avoid splashback. The Prophet (peace be upon him) urinated in soft ground at the base of a wall for this reason. Furthermore, it is recommended to urinate while sitting to prevent splashback, as Ibn Mas'ud considered standing while urinating a sign of impoliteness.
Supporting text
The permissibility of urinating while standing is narrated from Umar, Ali, Ibn Umar, Zayd ibn Thabit, Sahl ibn Sa'd, Anas, Abu Hurayrah, and Urwah. The Prophet (peace be upon him) once urinated standing up near a refuse pile, likely to establish permissibility without it being the usual practice, or due to a physical ailment.