Sunan Abi Dawud Book 4, Hadith 22
He would delay the evening prayer till he combined the evening and the night prayers when the twilight disappeared.
When the Messenger of Allah (ﷺ) proceeded before the sun had declined, he delayed the noon prayer till the time of the afternoon prayer, he would then alight and combine the two prayers. If the sun declined before he moved off, he would offer the noon prayer and rode (the beast) - may peace be upon him.
Abu Dawud said: The narrator Mufaddal was the judge of Egypt. His supplication was accepted by Allah; he was the son of Fudalah.
The Prophet (ﷺ) was engaged in the Battle of Tabuk. If he moved off before the sun had declined, he would delay the noon prayer till he would combine it with the afternoon prayer and would offer them together. If he moved off after the sun had declined, he would combine the noon and afternoon prayers, and then he proceeded; if he moved off before the evening prayer, he would delay the evening prayer; he would offer it along with the night prayer, he would delay the evening prayer; he would offer it along with the night prayer. If he moved off after the evening prayer, he would offer the night prayer earlier and offer it along with the evening prayer.
Abu Dawud said: This tradition has not been narrated by anyone except by Qutaibah.