Sa'd (may Allah be pleased with him) said: We were with the Messenger of Allah (peace and blessings be upon him) on a journey, and we had some dates with us. Safwan said to me: "Feed me these dates." I said: "These are only a few dates, and I fear that the others will ask for them; when the people stop to camp, you can eat with them." He said: "Feed me, for hunger has destroyed me," and he described the state he had reached. But I refused him, so he hamstrung the she-camel that was carrying the dates. This reached the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Tell Safwan to go away." The narrator said: That night he went around among the Companions of the Messenger of Allah (peace and blessings be upon him) and could not get through the night. Then he came to Sayyiduna Ali (may Allah be pleased with him) and said: "Where shall I go? Shall I go to disbelief?" Sayyiduna Ali (may Allah be pleased with him) went to the Prophet (peace and blessings be upon him) and told him (peace and blessings be upon him) of this, and he (peace and blessings be upon him) said: "Tell Safwan to join us."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5476