al-Hakam bin 'Utayba الحكم بن عتيبة · The Book of Purification and its Sunnah

The Messenger of Allah came to the garbage dump of some people and he urinated on it standing up.

The Messenger of Allah came to the garbage dump of some people and urinated while standing up. (Hasan) Shu'bah said: "That day, 'Asim said: 'Amash reported this from Abu Wa'il, from Hudhaifah, but he did not remember it (correctly). So I asked Mansur about it, and he narrated it to me from Abu Wa'il, from Hudhaifah, that the Prophet came to a dump of some people and urinated while standing.'"

"If anyone tells you that the Messenger of Allah urinated while standing, do not believe him, for I (always) saw him urinating while sitting down."

The Prophet was asked about seawater, and he said: "Its water is a means of purification, and its dead meat is permissible." (Hasan) Another chain with similar wording.

"The Messenger of Allah used to command us not to take off our leather socks for three days except in the case of sexual impurity, but not in the case of defecation, urine or sleep (i.e. during travel)."