Abu Dawud Book 2, Hadith Number 1201.

Chapter : On offering prayer by a traveller during journey while has doubt about its correct timing.

Narated By Anas ibn Malik : When the Apostle of Allah (PBUH) halted at a certain place (while on a journey), he would not leave that place till he offered the noon prayer. A man said to him: Even if in the middle of the day? He replied: Even if in the middle of the day.