Arabic (Original)
وَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا نَعَسَ أَحَدُكُمْ فِي صَلَاتِهِ فَلْيَنْصَرِفْ فَلْيَنَمْ.
English Translation
And the Messenger of Allah (peace and blessings be upon him) said: "When one of you feels drowsy during his prayer, let him withdraw and sleep."