Zakaat - Rules and modern issues

Those who don’t give Zakaat will be in trouble on the Day of Judgment

There is a Hadith in Sahih Muslim:

Translation: Hadhrat Abu Dhar (May Allah be well pleased with him) says that I went to the Holy Prophet (Sallallahu alaihi wa sallam).  He was sitting in the shadow of the Ka’aba.  One seeing me, He said: By the Lord of the Ka’aba!  They will be ruined.  I sat down, but then stood up out of restlessness and said:  O Prophet of Allah (Sallallahu alaihi wa sallam)!  I would offer my mother and father in lieu of you!  Who are they?  The Holy Prophet (Sallallahu alaihi wa sallam) said:  They are the mighty rich except those who spend in front, this side, that side and behind them and rich people like this are very rare.  The person who has camels, cattle or goats and does not give Zakaat on them, on the Day of Judgment they will all come fatter than they had ever been and will strike that person with their horns and trample him (or her) with their horns.  When the last animal will have finished trampling, the first will return to trample and until the reckoning of the people is over, this will go on happening.  (Sahih Muslim, Hadith No. 2347)