Hadith: No Muslim invokes Allah with a supplication that does not involve sin or severing ties of kinship, except that Allah will grant him one of three: either His supplication will be answered soon, or He will save it for him in the Hereafter, or He will avert from him an equivalent amount of evil." They said: Then we should do more. He said: "Allah is even more

عَنْ أَبِي سَعِيدٍ رضي الله عنه أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ:
«مَا مِنْ مُسْلِمٍ يَدْعُو بِدَعْوَةٍ لَيْسَ فِيهَا إِثْمٌ، وَلَا قَطِيعَةُ رَحِمٍ، إِلَّا أَعْطَاهُ اللهُ بِهَا إِحْدَى ثَلَاثٍ: إِمَّا أَنْ تُعَجَّلَ لَهُ دَعْوَتُهُ، وَإِمَّا أَنْ يَدَّخِرَهَا لَهُ فِي الْآخِرَةِ، وَإِمَّا أَنْ يَصْرِفَ عَنْهُ مِنَ السُّوءِ مِثْلَهَا» قَالُوا: إِذنْ نُكْثِرُ، قَالَ: «اللهُ أَكْثَرُ».
[صحيح] - [رواه أحمد] - [مسند أحمد: 11133]

Abu Sa‘īd (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said:
"No Muslim invokes Allah with a supplication that does not involve sin or severing ties of kinship, except that Allah will grant him one of three: either His supplication will be answered soon, or He will save it for him in the Hereafter, or He will avert from him an equivalent amount of evil." They said: Then we should do more. He said: "Allah is even more."
[Authentic hadith] - [Narrated by Ahmad] - [Musnad Ahmad - 11133]

Explanation

The Prophet (may Allah's peace and blessings be upon him) informed that when a Muslim supplicates Allah and asks for something that is not sinful, like asking for the facilitation of sin or injustice, nor does he ask for severing ties of kinship, like supplicating against his children or relatives, then Allah will grant him, through his supplication, one of three things: He will either hasten the fulfillment of his supplication and grant him what he asked for. Or Allah Almighty will delay it as a reward for him on the Day of Judgment by being elevated in rank or receiving mercy and forgiveness of misdeeds. Or He will prevent harm, in proportion to his supplication, from befalling him in his worldly life. Thereupon, the Companions said to the Prophet (may Allah's peace and blessings be upon him): Then we should supplicate more to attain one of these advantages. He (may Allah's peace and blessings be upon him) said: What Allah possesses is way more and greater than anything you could ask for, for His bounty is infinite and endless.