كتاب الطهارة
Read the English translation first, with the original Arabic directly underneath.
Narrated Abu Qatadah:
The Prophet (sal Allaahu alayhi wa sallam) said: When any one of you urinates, he must not touch his penis with his right hand, and when he goes to relieve himself he must not wipe himself with his right hand (in the privy), and when he drinks, he must not drink in one breath.
إِذَا بَالَ أَحَدُكُمْ فَلاَ يَمَسَّ ذَكَرَهُ بِيَمِينِهِ وَإِذَا أَتَى الْخَلاَءَ فَلاَ يَتَمَسَّحْ بِيَمِينِهِ وَإِذَا شَرِبَ فَلاَ يَشْرَبْ نَفَسًا وَاحِدًا