It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that he heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever does not give the zakat of his wealth, Allah Almighty will appoint a bald snake over him on the Day of Resurrection. He will run away, and the snake will chase after him until it puts a collar of itself around his neck." Then the Messenger of Allah (peace and blessings be upon him) recited the verse: "On the Day of Resurrection, their stinginess will become a collar around their necks."
Hadith Referenceالسنن المأثورة / باب ما جاء في صدقة الفطر / 375
Hadith Takhrijسنن ترمذی، التفسیر ، باب ومن سورۃ آل عمران، رقم : 3012 وقال حسن صحیح وقال الالبانی، صحیح ، سنن نسائی، الزکاۃ، باب التغلیظ فی حبس الزکاۃ، رقم : 2441