Majma al-Zawaid — Hadith 6268

A man named Fannaj narrates: I used to work in Dinbadh (a town in Yemen) and look after the land. Sayyiduna Ya'la bin Umayyah (may Allah be pleased with him) came as governor of Yemen, and with him were some men from among the Companions of the Prophet (peace and blessings be upon him). One of those who had come with him came to me while I was in the field watering the crops. He had walnuts in his sleeve. He sat down by a water channel, cracking those walnuts and eating them. Then he gestured to Fannaj and said: "O Persian, come here." He says: I went to him. That man said to Fannaj: "Will you undertake to plant these walnut trees by this water?" Fannaj asked him: "What benefit will that bring me?" The man said: "I heard the Prophet (peace and blessings be upon him) say, with these two ears of mine: 'Whoever plants a tree, then is patient in guarding it and tends it until it bears fruit, then for whatever anyone obtains from its fruit, that person receives the reward of charity in the court of Allah Almighty.'" Fannaj asked him: "Did you hear this yourself from the Prophet (peace and blessings be upon him)?" He said: "Yes!" Fannaj said: "Then I undertake it." The narrator says: That is how the walnuts of Dinbadh began.
Imam Ahmad recorded it; its chain contains a narrator, Fannaj, whom Ibn Abi Hatim mentioned without either declaring him trustworthy or criticising him, and its remaining narrators are thiqat (trustworthy).