Sunan Ibn Majah
1828
Sahih+1

It was narrated that:Qais bin Sa'ad said: “The Messenger of Allah (ﷺ) enjoined Sadaqatul-Fitr upon is before (the command of) Zakat was revealed. He neither ordered us (to pay) nor forbade us (from paying it), so we did it.”

SahihShuaib Al Arnaut
SahihZubair Ali Zai