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
Authentic hadithعن معاوية بن أبي سفيان رضي الله عنهما قال: قال رسول الله صلى الله عليه وسلم : «لا تُلْحِفُوا في المسأَلة، فوالله لا يَسْألني أحدٌ منكم شيئًا، فَتُخْرِجَ له مسألته منِّي شيئًا وأنا له كارِهٌ، فيُبَارَك له فيما أَعْطَيتُه».
Abu ‘Abdur-Rahmān Mu‘āwiyah ibn Abi Sufyān (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said: "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."
Explanation
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.
Source · Narrated by Muslim
From the Hadith Encyclopedia (hadeethenc.com).