Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: On the night when the Messenger of Allah (peace and blessings be upon him) slept through the Fajr prayer until the sun rose, there were also two camel-drivers (who drive camels by singing to them) with us.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10504