Hadith: Your supplication is answered as long as one of you is not in haste, saying: I have supplicated to my Lord, but He has not yet answered me

عن أبي هريرة رضي الله عنه مرفوعاً: يُستجاب لأحدكم ما لم يَعْجَلْ: يقول: قد دعوت ربي، فلم يستجب لي». وفي رواية لمسلم: «لا يزال يُستجاب للعبد ما لم يَدْعُ بإثم، أو قطيعة رحم، ما لم يَسْتَعْجِلْ» قيل: يا رسول الله ما الاستعجال؟ قال: «يقول: قد دعوت، وقد دعوت، فلم أر يستجب لي، فَيَسْتَحْسِرُ عند ذلك ويَدَعُ الدعاء».
[صحيح] - [متفق عليه]

Abu Hurayrah (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: “The supplication of one of you is answered, as long as he is not in haste, saying: ‘I have supplicated to my Lord, but He did not answer me.'" In another narration by Muslim: “The supplication of a slave will continue to be answered, as long as he does not ask for a sin or sever a tie of kinship, and is not hasty.” It was said: “O Messenger of Allah, what is hastiness?” He said: “It is to say: 'I have supplicated and supplicated, but I have not seen it has been answered.' He would then lose hope and stop supplicating.”
[Authentic hadith] - [Narrated by Bukhari & Muslim]

Explanation

The Prophet (may Allah's peace and blessings be upon him) tells that Allah, the Almighty, answers the invocations of His slave, so long as he does not supplicate for an act of disobedience or for severing kinship ties, and so long as he is not hasty. The Prophet (may Allah's peace and blessings be upon him) was asked about the nature of haste that prevents the fulfillment of supplication. He explained that one complains that he supplicates repeatedly but gets no answer. Upon that, he thinks that his invocation is not going to be answered out of haste, so he stops asking Allah, the Almighty.