‘Abdallah b. Tha'laba, or Tha'laba b. ‘Abdallah b. Abu Su'air* reported on his father’s authority that Allah's Messenger ﷺ said, “A sa’ of wheat** is to be taken from every two, young or old, freeman or slave, male or female. Those of you who are rich will be purified by Allah and those of you who are poor will have more than they gave returned by Him to them.” Abu Dawud transmitted it. * Abu Dawud, zakat, 21 gives the name as above, but others often give b. Su'air. Ibn 'Abd al-Barr in Isti'ab and Ibn Hajar in Tahdhib give b. Su'air, adding that b. Abu Su'air also occurs. ** The transmitter is not sure which word for "wheat” was used, so he gives either burr or qamh.