The hadith states that the Prophet Muhammad ﷺ once urinated while standing.
Reference: (Sahih al-Bukhari, 225; Sahih Muslim, 613)
Since this is considered contrary to the dignity of prophethood, such hadiths are unacceptable.First Point
Nowhere in the Quran or Sunnah is it prohibited to urinate while standing.
Second Point
The hadith also provides a reason for urinating while standing: there was garbage there, and certainly it was a place where sitting was not possible or there was a high chance of impurity. Accordingly, Ibn al-Qayyim, may Allah have mercy on him, states:
وَالصَّحِيحُ أَنَّهُ إِنَّمَا فَعَلَ ذَلِكَ تَنَزُّهًا وَبُعْدًا مِنْ إِصَابَةِ الْبَوْلِ، فَإِنَّهُ إِنَّمَا فَعَلَ هَذَا لَمَّا أَتَى سُبَاطَةَ قَوْمٍ – وَهُوَ مَلْقَى الْكُنَاسَةِ – وَتُسَمَّى الْمَزْبَلَةَ، وَهِيَ تَكُونُ مُرْتَفِعَةً، فَلَوْ بَالَ فِيهَا الرَّجُلُ قَاعِدًا لَارْتَدَّ عَلَيْهِ بَوْلُهُ، وَهُوَ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ اسْتَتَرَ بِهَا وَجَعَلَهَا بَيْنَهُ وَبَيْنَ الْحَائِطِ فَلَمْ يَكُنْ بَدٌّ مِنْ بَوْلِهِ قَائِمًا وَاللَّهُ أَعْلَمُ
Translation: The correct understanding is that the Prophet Muhammad ﷺ did this to avoid urine splashes and to keep distance when he came to a place where people threw garbage, etc. It was a raised place such that if someone relieved himself there, the drops of urine would come toward the person. The Prophet ﷺ avoided the splashes, so he urinated between a wall and a garbage pit, and it was necessary to stand to avoid impurity and urine splashes.
Another Reason
Another reason has also been stated that it was due to some illness, therefore Imam Shafi'i, may Allah have mercy on him, says:
وَالْعَرَبُ تَسْتَشْفِي مِنْ وَجَعِ الصُّلْبِ بِالْبَوْلِ قَائِمًا
Translation: Arabs sometimes relieved their back pain by urinating while standing.
Summary
Whatever the reason, Islamic jurists agree that it is permissible to urinate standing due to an excuse, and the practice of the Prophet Muhammad ﷺ serves as guidance for this permissibility.
Reference: See: Maraqi al-Falah by al-Sharnabli 1/22, Mawahib al-Jalil Sharh Mukhtasar al-Khalil by al-Hattab al-Ra'ini, 1/386, Al-Majmu'
