Sahih Muslim Book 6, Hadith 26
He prayed while travelling.
The Apostle of Allah (ﷺ) said in Mina the prayer of a traveller (short prayer) ; Abu Bakr and 'Umar did the same and 'Uthmia did it for eight years or six years. Hafs (one of the narrators) said: Ibn 'Umar would also say two rak'ahs at Mina and then go to bed. I said to him: O uncle, I wish you could have said two rak'ahs (of Sunnah prayer after shorenting the Fard prayer). He said: Were I to do that, I would have completed the prayer.
I heard 'Abd al-Rahman as saying; 'Uthman led us four rak'ahs of prayer at Mina. It was reported to Abdullah b. Mas'ud and he recited:" Surely we are Allah's and to Him shall we return," and then said: I prayed with the Messenger of Allah (ﷺ) at Mina two rak'ahs of prayer. I prayed along with Abu Bakr al-Siddiq two rak'ahs of prayer at Mina. I prayed along with 'Umar b. Khattab two rak'ahs of prayer at Mina. I wish I had my share of the two rak'ahs acceptable (to God) for the four rak'ahs.