Musannaf Ibn Abi Shayba 3:5854

Waki’ narrated to us, he said: ‘Imran bin Hudair narrated to us, from ‘Abdullah bin Shaqiq al-‘Uqayli, who said: A man said to Ibn ‘Abbas, "The prayer," but he remained silent. Then he said to him, "The prayer," but he remained silent. Then he said to him, "The prayer," three times. He (Ibn ‘Abbas) said, "May you have no father! Are you teaching us the prayer? We used to combine the two prayers during the time of the Prophet, may Allah bless him and grant him peace," meaning while traveling.