Umar said, "Messenger of Allah, I heard so-and-so speaking well of you, mentioning that you gave him two Dinars."He replied, "But so-and-so does not say the same nor speaks well of me, even though I gave him anywhere from ten to a hundred," or he said, "to two hundred. One of them asks me for something, I give it to him, and he walks off carrying it under his arm, when in truth it is nothing but fire for them."Umar asked, "Messenger of Allah, then why do you give to them?"He answered, "They refuse anything but to keep asking me, and Allah refuses to let me be stingy."
حدثنا يحيى بن آدم حدثنا أبو بكر عن الأعمش عن أبي صالح
قال عمر يا رسول الله سمعت فلانا يقول خيرا ذكر أنك أعطيته دينارين قال لكن فلان لا يقول ذلك ولا يثني به لقد أعطيته ما بين العشرة إلى المائة أو قال إلى المائتين وإن أحدهم ليسألني المسألة فأعطيها إياه فيخرج بها متأبطها وما هي لهم إلا نار قال عمر يا رسول الله فلم تعطيهم قال إنهم يأبون إلا أن يسألوني ويأبى الله لي البخل
Its isnad is sahih, and it was likewise graded sahih in Majma at 3/94. The hadith is also found in Ibn Hibban at 216, no. 849 (Mawarid), and in Hakim at 1/46, who graded it sahih, and Dhahabi agreed with him.