I heard the Messenger of Allah ﷺ say, "Do not be persistent in begging. By Allah, no one asks me for anything and obtains it through his persistent asking only to find blessing in what I have given him."
حدثنا سفيان عن عمرو عن ابن منبه عن أخيه
سمعت رسول الله ﷺ يقول لا تلحفوا في المسألة فوالله لا يسألني أحد شيئا فتخرج له مسألته فيبارك له فيه
Its isnad is sahih. No one explicitly stated which of Ibn Munabbih's sons narrated from the other, though Muslim made this explicit in 2/718, no. 1038, saying, from Abdullah bin Wahb bin Munabbih, from his brother Hammam, in the chapter on zakat, on the prohibition of asking. Nasai made the first explicit but did not make the second explicit, 5/97, no. 2593.