Muwatta Malik · Hadith 597
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، أَنَّهُ قَالَ سَمِعْتُ عَبْدَ اللَّهِ بْنَ عُمَرَ، وَهُوَ يُسْأَلُ عَنِ الْكَنْزِ، مَا هُوَ فَقَالَ هُوَ الْمَالُ الَّذِي لاَ تُؤَدَّى مِنْهُ الزَّكَاةُ .
Yahya related to me from Malik that Abdullah ibn Dinar said, "I heard Abdullah ibn Umar being asked what kanz was and he said, 'It is wealth on which zakat has not been paid
Mauquf Sahih · Salim al-Hilali