Nasai

36. Commentary:
➊ It is prohibited to urinate in the place designated for ritual bath (ghusl), because later the water of the ritual bath will fall there and splashes will occur; furthermore, the impurity will spread due to the mixing with water. Reason itself demands that one should not perform purification in a place of impurity, nor commit impurity in a place of purification. Human nature finds this repugnant, even if there is no likelihood of impurity actually contacting oneself—just as an intelligent person would not tolerate eating or drinking while sitting near filth. This issue is of a similar nature. Some jurists are of the opinion that if urine does not collect there, then there is no harm in urinating; however, this is contrary to sound natural disposition (fitrah), and Islam is the religion of natural disposition. Moreover, this also appears to contradict the general wording of the explicit text.
➋ Shaykh al-Albani rahimahullah has declared the entire hadith authentic except for the wording of «فَإِنَّ عَامَّةَ الْوَسْوَاسِ مِنْهُ». And his opinion seems stronger, because this phrase is not supported by other evidences. And Allah knows best. See: [صحیح سنن النسائي ، حدیث : 36]

English Commentary:
1:
This prohibition pertains to such bathhouses (ghusl khanah) in which urine is absorbed into the ground or remains stagnant. In constructed bathhouses where urine flows away immediately upon contact with water, this prohibition does not apply (see Sunan Ibn Majah, no. 304).

2:
When Imam Tirmidhi uses the term "gharib" regarding a hadith, such narrations are often weak. A review of all such ahadith reveals this point. This hadith is also weak (see Da'if Abi Dawud, no. 6). However, the first part concerning "the prohibition of urinating in the bathhouse" is authentic based on corroborating evidences.

3:
The meaning is that all whisperings (waswasah) that arise are created by Allah Ta'ala; urinating in bathhouses has no connection to this.

Benefits and Issues:
This narration is weak; however, the next hadith in Sunan Abi Dawud, hadith [28], is authentic and carries the same meaning.

The aforementioned narration has been declared weak in its chain of transmission by our esteemed researcher, who has further stated that Hadith number 27 of Sunan Abu Dawood suffices in this regard, as it possesses a sound chain of transmission.

In addition, Shaykh al-Albani rahimahullah has also declared this narration to be authentic. In any case, caution and respect for the Sunnah demand that one should avoid urinating in the bathhouse.