Al-Shawkānī’s remark in al-Sayl, 1/67, that “urinating while standing, though not unlawful, is still severely disliked,” is of no weight.
His statement under no. 10 reads: “It is narrated from Ḥudhayfah that the Prophet ﷺ came to a rubbish heap belonging to some people and urinated standing … it was transmitted by the compilers as a group.”
I say: The ḥadith is unquestionably authentic, so opening it with the phrase “it is narrated (ruwiya)”—which, by agreement of the ḥadith scholars, suggests weakness—was improper. He should have said “it is reported (warada),” or a similar wording that conveys the ḥadith’s established soundness. See Principle 13.
His statement under no. 11: “One must remove the filth from the two passages with a stone … or with water alone, or with both together.”
I say: No sound report from the Prophet ﷺ confirms combining water and stones in istinjāʾ (cleansing after relieving oneself). I fear that advocating both together borders on excess in religion, for his ﷺ practice was to suffice with either one of them. “The best guidance is the guidance of Muhammad ﷺ, and the worst of matters are newly-invented ones …”.
As for the ḥadith claiming that the people of Qubāʾ combined water and stones and that, because of them, the verse was revealed: “Within it are men who love to purify themselves” (Qurʾān 9:108), its chain is weak and cannot be cited as proof; al-Nawawī, Ibn Ḥajar, and others graded it weak. The original report in Abū Dāwūd and elsewhere is from Abū Hurayrah and does not mention stones, which is why Abū Dāwūd placed it in “The Chapter on Cleansing with Water.” It has many corroborations, none of which mention stones. I have clarified this in Ṣaḥīḥ Sunan Abī Dāwūd, no. 34.