Ahmed bin Manay' أحمد بن منيع · The Book on Traveling

"Imran bin Husain was asked about the traveler's prayer. He said: 'I performed Hajj with the Messenger of Allah, and he prayed two Rak'ah. I performed Hajj with Abu Bakr, and he prayed two Rak'ah and with Umar, and he prayed two Rak;ah; and with Uthman for six years of his Khilafah, or eight years, and he prayed two Rak'ah."

that Anas bin Malik said: "We went with the Messenger of Allah from Al-Madinah to Makkah, and he prayed two Rak'ah." He said: "I said to Anas: 'How long did Messenger of Allah stay in Makkah?' He said: 'Ten (days).'"