Sahih Muslim 1037 a
Mu'awiya said:
Be cautious about ahadith except those which were current during the reign of Umar, for he exhorted people to fear Allah, the Exalted and mMajestic. I heard the Messenger of Allah (ﷺ) as saying: He upon whom Allah intends to bestow goodness, He confers upon him an insight in religion; and I heard the Messenger of Allah (ﷺ) as saying: I am the treasurer. To one whom I give out of (my own) sweet will, he would be blessed in that, but he whom I give (yielding to) his constant begging and for his covetousness is like one who would eat, but would not be satisfied.
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا زَيْدُ بْنُ الْحُبَابِ، أَخْبَرَنِي مُعَاوِيَةُ بْنُ صَالِحٍ، حَدَّثَنِي رَبِيعَةُ بْنُ يَزِيدَ الدِّمَشْقِيُّ، عَنْ عَبْدِ اللَّهِ بْنِ عَامِرٍ الْيَحْصَبِيِّ، قَالَ سَمِعْتُ مُعَاوِيَةَ، يَقُولُ إِيَّاكُمْ وَأَحَادِيثَ إِلاَّ حَدِيثًا كَانَ فِي عَهْدِ عُمَرَ فَإِنَّ عُمَرَ كَانَ يُخِيفُ النَّاسَ فِي اللَّهِ عَزَّ وَجَلَّ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم وَهُوَ يَقُولُ ‏"‏ مَنْ يُرِدِ اللَّهُ بِهِ خَيْرًا يُفَقِّهْهُ فِي الدِّينِ ‏"‏ ‏.‏ وَسَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏"‏ إِنَّمَا أَنَا خَازِنٌ فَمَنْ أَعْطَيْتُهُ عَنْ طِيبِ نَفْسٍ فَيُبَارَكُ لَهُ فِيهِ وَمَنْ أَعْطَيْتُهُ عَنْ مَسْأَلَةٍ وَشَرَهٍ كَانَ كَالَّذِي يَأْكُلُ وَلاَ يَشْبَعُ ‏"‏ ‏.‏