Nafi' narrates from Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "When one of you feels sleepy on Friday at the place of prayer inside the mosque, let him change his place." By al-salah (the prayer) is meant the place of prayer.
The attribution of this hadith to the Prophet (marfu') is not established; what is well known is that it is the saying of Ibn Umar himself.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5926