He (Urwah) said: "While standing for the prayer he (Abdullah bin Al-Arqam) took a man by the hand leading him forward, he (Abdullah) was in front of the people, and he said: 'I heard Messenger of Allah say: "When standing for the prayer and one of you finds that he has to relieve himself then let him relieve himself first."  

أُقِيمَتِ الصَّلاَةُ فَأَخَذَ بِيَدِ رَجُلٍ فَقَدَّمَهُ وَكَانَ إِمَامَ قَوْمِهِ وَقَالَ سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ إِذَا أُقِيمَتِ الصَّلاَةُ وَوَجَدَ أَحَدُكُمُ الْخَلاَءَ فَلْيَبْدَأْ بِالْخَلاَءِ قَالَ وَفِي الْبَابِ عَنْ عَائِشَةَ وَأَبِي هُرَيْرَةَ وَثَوْبَانَ وَأَبِي أُمَامَةَ