“Those who believe, and do deeds of righteousness, and establish regular prayers and regular charity, will have their reward with their Lord: on them shall be no fear, nor shall they grieve” (Surah Bakaara, Ayah 277)

Rasulullah (saw) says

“Islam is based on five principles: to testify that there is no god but Allah and tat Mohammed is the messenger of Allah, to pray Salah, to give Zakaat, to perform Hajj and to fast during the month of Ramadan.”

In order to state its importance, in many Ayahs, Zakaat has been mentioned straight after Salah and have been mentioned together.

For those who do not give Zakaat, Allah (swt) says in Surah Al-I Imran, Ayah 180

“And let not those who covetously withhold of the gifts which Allah has given them of Allah’s grace, think that it is good for them: Nay, it will be the worse for them: soon shall the things which they covetously withheld be tied to their necks like a twisted collar, on the Day of Judgment. To Allah belongs the heritage of the heavens and the earth; and Allah is well-acquainted with all that you do”

Rasulullah (saw) says

“On the Day of Judgement, the properties of a man which Allah blessed him with, but from which he never gave Zakaat, would turn into a huge poisonous snake with black dots in each eye and this snake would wrap himself around the neck of them. Then the snake will grab the two sideas of the man’s chin and say ‘I am your belongings in the world which you loved so much, I am your wealth’”

Hz Abu Bakr, who was appointed Caliph after the death of Rasulullah (saw), said of those who do not give Zakaat:

“I swear in the name of Allah, that I will wage war on those who split Zakaat from Salah. Because Zakaat is a financial right. I swear in the name of Allah, that if they do not give me what they gave to Rasulullah (saw), even if it is the hair of a camel, I will wage war on them”