Sayyiduna Sahl bin al-Hanzaliyyah (may Allah be pleased with him) says that Uyaynah bin Hisn and al-Aqra' bin Habis (may Allah be pleased with them both) came to the Prophet (peace and blessings be upon him). The two of them asked him (peace and blessings be upon him), and he (peace and blessings be upon him) ordered that they be given what they had asked for, and he ordered Sayyiduna Mu'awiyah (may Allah be pleased with him) to write down for them what they had asked for. The narrator says that al-Aqra' (may Allah be pleased with him) wrapped his letter in his turban and went off, while Uyaynah (may Allah be pleased with him) took his letter and came to the Prophet (peace and blessings be upon him) and said: "O Muhammad (peace and blessings be upon him)! I am going to carry this letter to my people, and I myself do not know what is in it."
The narrator says that the Prophet (peace and blessings be upon him) took it, looked into it and said: "In it is written what I ordered for you."
Then he mentioned the long hadith, and the Prophet (peace and blessings be upon him) said: "Whoever asks while he has no need of it (that is, he does not need it) is only gathering more of the fire of Hell." The noble Companions (may Allah be pleased with them) asked: O Prophet of Allah! What is the sufficiency after which there is no room for asking? He (peace and blessings be upon him) said: "That he has enough to eat his fill for a day and a night, or a night and a day."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الصدقات / 13212