Didache. The Apostolic Fathers with an English translation In Two Volumes. Vol. I. Lake, Kirsopp, translator. Cambridge, MA: Harvard University Press; London: William Heinemann Ltd. 1912.

If thou makest bread, take the first-fruits, and give it according to the commandment.

Likewise when thou openest a jar of wine or oil, give the firstfruits to the prophets.

Of money also and clothes, and of all your possessions, take the firstfruits, as it seem best to you, and give according to the commandment.