Quran
"O you who believe! Spend of the good things which you (legally) earned, and of that which We have produced from the earth for you..."
​(Al-Baqarah: Verse 267) 
See more Quranic verses on Zakat and Charity here.

Hadith
"(The superstructure of) Islam is raised on five (pillars): to utter an attestation of faith, performance of prayer, payment of Zakat, fast of Ramadan and pilgrimage (to Makkah)." (Narrated by Ibnu Umar R.A.)
See more Hadith on Zakat here. 

Fatwa
To view Fatwa on Zakat in Singapore, click here