Sunan an Nasai
2487
Sahih+2

It was narrated from Abu Sa'eed Al_khudri that the Prophet said:"No sadaqah is due on less than five Awaq, no Sadaqah is due on less than five Dhawd, no Sadaqah is due on less than five Awsuq

SahihAbu Ghuddah
SahihAl-Albani