The Book of Zakat
وَحَدَّثَنِي حَرْمَلَةُ بْنُ يَحْيَى، أَخْبَرَنِي ابْنُ وَهْبٍ، أَخْبَرَنِي يُونُسُ، عَنِ ابْنِ شِهَابٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم أَنَّهُ قَالَ " لَوْ كَانَ لاِبْنِ آدَمَ وَادٍ مِنْ ذَهَبٍ أَحَبَّ أَنَّ لَهُ وَادِيًا آخَرَ وَلَنْ يَمْلأَ فَاهُ إِلاَّ التُّرَابُ وَاللَّهُ يَتُوبُ عَلَى مَنْ تَابَ " .Anas b. Malik reported Allah's Messenger (ﷺ) as saying:If there were two valleys of gold for the son of Adam, he would long for another one. and his mouth will not be filled but with dust, and Allah returns to him who repents
From Sahih Muslim, whose reports the scholars accept as authentic.