Nafie' نافع مولى ابن عمر · The Book on Traveling

"I traveled with the Prophet, Abu Bakr, Umar, and Uthman; they would pray Zuhr and Asr as two Rak'ah and two Rak'ah, not praying before them nor after them." And Ibn Umar said: "If I was going to pray before it or after it then I would pray it complete."

"I prayed with the Prophet both, while a resident and while traveling. So I prayed four for Zuhr with him as a resident, and two Rak'ah after it. I prayed two Rak'ah for Zuhr with him while traveling and two Rak'ah after it, and two Rak'ah for Asr, and he did not pray anything after it. Maghrib while a resident and traveling is the same; three Rak'ah, it is not decreased as a resident nor while traveling. It is Witr…

"Ibn Umar had been requested to urgently attend to one of his wives, so he hurried en route and delayed Maghrib until the twilight disappeared, then he dismounted to combine them (the prayers). Then he informed them that the Messenger of Allah would do that when he was in a hurry on a trip."