Do not be importunate in asking (for something), for by Allah, if one of you asked me for something and I gave it to him while I am reluctant, there will be no blessing in what I gave him

Mu‘āwiyah (may Allah be pleased with him) relates that the Prophet (may Allah's peace and blessings be upon him) forbade people from being persistent in asking for something, noting that such persistence removes the blessing from the given thing. Then, the Prophet swore that if someone asked him for something in a persistent manner and he gave it to him reluctantly, that thing would be bereft of blessing due to the persistent asking.