Khalid ibn 'Umair and Shuwais Abur-Ruqad said

“'Umar ibn al-Khattab dispatched 'Utba ibn Ghazwan, and he said: ‘Go away, you and whoever is with you, until you reach the most remote countries of the Arabs and the nearest countries of the non-Arabs!’ They therefore advanced until, when they reached al-Mirbad, they found this soft stone-like clay, so they said: ‘What is this?’ They were told: ‘This is Basra,’ so they traveled until they were in the vicinity of the small bridge. They said: ‘Here is our appointed destination,’ so they alighted and related the story from beginning to end. 'Utba ibn Ghazwan said: ‘I found myself the seventh of seven with Allah’s Messenger (Allah bless him and give him peace). We ate nothing but tree-leaves until the corners of our mouths were covered with ulcers, so I picked up a garment which I divided between me and Sa'd, for there was not one of us among those seven who was not the governor of a city, and you will put the governors to the test after us.”