Abu Sa'id al-Khudri reported Allah's Messenger (ﷺ) as saying:
No Sadaqa is payable on less than five wasqs of dates or grains. (IT)
Reference (IT): Sahih Muslim 979 e (IT)
In-book reference (IT): Book 12, Hadith 5 (IT)
USC-MSA web (English) reference(deprecated numbering scheme): Book 5, Hadith 2138 (IT)