Sahih al-Bukhari 6957, 6958
Narrated Abu Huraira:
Allah's Messenger (ﷺ) said, "On the Day of Resurrection the Kanz (Treasure or wealth of which, Zakat has 
not been paid) of anyone of you will appear in the shape of a huge bald headed poisonous male snake 
and its owner will run away from it, but it will follow him and say, 'I am your Kanz.'" The Prophet (ﷺ) 
added, "By Allah, that snake will keep on following him until he stretches out his hand and let the 
snake swallow it." Allah's Messenger (ﷺ) added, "If the owner of camels does not pay their Zakat, then, on 
the Day of Resurrection those camels will come to him and will strike his face with their hooves." 
Some people said: Concerning a man who has camels, and is afraid that Zakat will be due so he sells 
those camels for similar camels or for sheep or cows or money one day before Zakat becomes due in 
order to avoid payment of their Zakat cunningly! "He has not to pay anything." The same scholar said, 
"If one pays Zakat of his camels one day or one year prior to the end of the year (by the end of which 
Zakat becomes due), his Zakat will be valid."
حَدَّثَنِي إِسْحَاقُ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، حَدَّثَنَا مَعْمَرٌ، عَنْ هَمَّامٍ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ يَكُونُ كَنْزُ أَحَدِكُمْ يَوْمَ الْقِيَامَةِ شُجَاعًا أَقْرَعَ، يَفِرُّ مِنْهُ صَاحِبُهُ فَيَطْلُبُهُ وَيَقُولُ أَنَا كَنْزُكَ‏.‏ قَالَ وَاللَّهِ لَنْ يَزَالَ يَطْلُبُهُ حَتَّى يَبْسُطَ يَدَهُ فَيُلْقِمَهَا فَاهُ ‏"‏‏.‏ وَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ إِذَا مَا رَبُّ النَّعَمِ لَمْ يُعْطِ حَقَّهَا، تُسَلَّطُ عَلَيْهِ يَوْمَ الْقِيَامَةِ، تَخْبِطُ وَجْهَهُ بِأَخْفَافِهَا ‏"‏‏.‏ وَقَالَ بَعْضُ النَّاسِ فِي رَجُلٍ لَهُ إِبِلٌ، فَخَافَ أَنْ تَجِبَ عَلَيْهِ الصَّدَقَةُ، فَبَاعَهَا بِإِبِلٍ مِثْلِهَا، أَوْ بِغَنَمٍ، أَوْ بِبَقَرٍ، أَوْ بِدَرَاهِمَ، فِرَارًا مِنَ الصَّدَقَةِ بِيَوْمٍ، احْتِيَالاً فَلاَ بَأْسَ عَلَيْهِ، وَهْوَ يَقُولُ إِنْ زَكَّى إِبِلَهُ قَبْلَ أَنْ يَحُولَ الْحَوْلُ بِيَوْمٍ أَوْ بِسَنَةٍ، جَازَتْ عَنْهُ‏.‏