[Machine] It is said that the Prophet ﷺ urinated while standing with a wound on his foot. The imam, may Allah have mercy on him, said that it was previously known that the Arabs would use urine to treat a pain in the joints, so perhaps the Prophet did so at that time due to the pain in his foot. Ash-Shafi'i, may Allah have mercy on him, mentioned this incident in a similar manner. It is also said that the Prophet did so because he could not find a place or a spot to sit, and Allah knows best.  

أَنَّ النَّبِيَّ ﷺ بَالَ قَائِمًا مِنْ جُرْحٍ كَانَ بِمَأْبِضِهِ قَالَ الْإِمَامُ رَحِمَهُ اللهُ تَعَالَى وَقَدْ قِيلَ كَانَتِ الْعَرَبُ تَسْتَشْفِي لِوَجَعِ الصُّلْبِ بِالْبَوْلِ قَائِمًا فَلَعَلَّهُ كَانَ بِهِ إِذْ ذَاكَ وَجَعُ الصُّلْبِ وَقَدْ ذَكَرَهُ الشَّافِعِيُّ رَحِمَهُ اللهُ تَعَالَى بِمَعْنَاهُ وَقِيلَ إِنَّمَا فَعَلَ ذَلِكَ لِأَنَّهُ لَمْ يَجِدْ لِلْقُعُودِ مَكَانًا أَوْ مَوْضِعًا وَاللهُ أَعْلَمُ