كتاب التفسير
65  
Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
(6)
The Statement of Allah: "...And those who hoard up gold and silver (AI-Kanz—the money, the Zakãt of which has not been paid) and spend it not in the Way of Allah—announce to them a painful torment." (V.9:34)
(6)
Sahih al-Bukhari 4659

Narrated Abu Huraira:

Allah's Messenger (ﷺ) said, "The Kanz (money, the Zakat of which is not paid) of anyone of you will appear in the form of bald-headed poisonous male snake on the Day of Resurrection."

حَدَّثَنَا الْحَكَمُ بْنُ نَافِعٍ، أَخْبَرَنَا شُعَيْبٌ، حَدَّثَنَا أَبُو الزِّنَادِ، أَنَّ عَبْدَ الرَّحْمَنِ الأَعْرَجَ، حَدَّثَهُ أَنَّهُ، قَالَ حَدَّثَنِي أَبُو هُرَيْرَةَ ـ رضى الله عنه ـ أَنَّهُ سَمِعَ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏ "‏ يَكُونُ كَنْزُ أَحَدِكُمْ يَوْمَ الْقِيَامَةِ شُجَاعًا أَقْرَعَ ‏"‏‏.‏
Reference : Sahih al-Bukhari 4659
In-book reference : Book 65, Hadith 181
USC-MSA web (English) reference : Vol. 6, Book 60, Hadith 182
  (deprecated numbering scheme)