عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو رَضِيَ اللَّهُ عَنْهُمَا أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ الْقُلُوبُ أَوْعِيَةٌ وَبَعْضُهَا أَوْعَى مِنْ بَعْضٍ فَإِذَا سَأَلْتُمُ اللَّهَ عَزَّ وَجَلَّ أَيُّهَا النَّاسُ فَاسْأَلُوهُ وَأَنْتُمْ مُوقِنُونَ بِالْإِجَابَةِ فَإِنَّ اللَّهَ لَا يَسْتَجِيبُ لِعَبْدٍ دَعَاهُ عَنْ ظَهْرِ قَلْبٍ غَافِلٍ
It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: Hearts are like vessels, and some hearts are more receptive to remembrance than others. So, O people! When you ask Allah Almighty, do so with the certainty that your supplication will be accepted. Indeed, Allah Almighty does not accept the supplication of a servant who prays with a heedless and inattentive heart.