´It was narrated from Mu'awiyah that the Messenger of Allah said:` "Do not be demanding when asking. If one of you asks me for anything and I give it reluctantly, there will be no blessing in it."
Explanation & Benefits
Hafiz Muhammad Ameen
Insistence, that is, to persistently ask, means that the petitioner does not leave the one being asked alone until he obtains the desired thing from him. For the person for whom asking is permissible, insistence is also prohibited for him. “I do not like to give it to him.” You (sallallahu alayhi wa sallam) were the most generous of all. Your not liking (to give) is proof that he is not deserving; therefore, even if he takes something (by insisting), there will be no blessing in it from Allah, because the undeserving person is never satisfied—he always remains needy.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 2594