al-Hasan al-Basri الحسن البصري · The Book of Purification

"None of you should urinate in the place where he bathes, for most Waswas (devilish whispers) come from that." I.e., with regard to whether the urine has soiled his body or not.

It was narrated from Al-Muhajir bin Qunfudh that he greeted the Prophet (ﷺ) with Salam while he was urinating, and he did not return the greeting until he had performed Wudu'. When he had performed Wudu' he returned the greeting.

It was narrated from Al-Mughirah that the Prophet (ﷺ) performed Wudu', and he wiped the forehead, the 'Imamah, and over the Khuff. (Another chain)

"When (a man) sits between the four parts of his wife's body and exerts himself, then Ghusl becomes obligatory."