Abu Dawud Book 2, Hadith Number 1204.
Narated By Mu’adh ibn Jabal : On the expedition to Tabuk if the sun had passed the meridian before the apostle of Allah (PBUH) moved off, he combined the noon and the afternoon prayers; but if he moved off before the sun had passed the meridian, he delayed the noon prayer till he halted for the afternoon prayer. He acted similarly for the sunset prayer; if the sun set before he moved off, he combined the sunset and the night prayers, but if he moved off before sunset, he delayed the sunset prayer till he halted for the night prayer and then combined them.
Abu Dawud said: Hisham b. ‘Urwah narrated this tradition from Husain b. ‘Abd Allah, from Kuraib on the authority of Ibn ‘Abbas from the Prophet (PBUH) like the tradition narrated by Mufaffal and al-Laith.