Musnad Ahmad 1017:63

Zayd ibn al-Hubab narrated to us, Husayn narrated to me, Abdullah ibn Buraydah narrated to me, he said: I heard Buraydah saying: Salman came to the Messenger of Allah, may Allah bless him and grant him peace, when he arrived in Medina, with a tray upon which were fresh dates. He placed it before the Messenger of Allah, may Allah bless him and grant him peace. The Messenger of Allah, may Allah bless him and grant him peace, said: "What is this, O Salman?" He said: "It is a charity for you and your companions." He said: "Remove it, for we do not eat charity." So he removed it. The next day, he came with the like of it and placed it before him. He said: "What is this, O Salman?" He said: "It is a charity for you and your companions." He said: "Remove it, for we do not eat charity." So he removed it. The next day, he came with the like of it, carrying it, and placed it before him. He said: "What is this, O Salman?" He said: "It is a gift for you." The Messenger of Allah, may Allah bless him and grant him peace, said to his companions: "Stretch forth [your hands]." He [Salman] looked at the seal [of Prophethood] that was on the back of the Messenger of Allah, may Allah bless him and grant him peace, and he believed in him. He was [owned] by the Jews, so the Messenger of Allah, may Allah bless him and grant him peace, purchased him for such and such number of dirhams, and on the condition that he plant palm trees and work among them until they bear fruit. He said: The Messenger of Allah, may Allah bless him and grant him peace, planted the palm trees, except for one palm tree which Umar planted. The palm trees bore fruit that same year, but the [one] palm tree did not. The Messenger of Allah, may Allah bless him and grant him peace, said: "What is the matter with this one?" Umar said: "I planted it, O Messenger of Allah." He said: So the Messenger of Allah, may Allah bless him and grant him peace, pulled it out, then planted it, and it bore fruit that same year.