Sirach 7:31

Ben Sira, Ecclesiasticus

29 With all your soul fear the Lord, and revere his priests. 30 With all your might love your Maker, and do not neglect his ministers. 31 Fear the Lord and honor the priest, and give him his portion, as you have been commanded: the first fruits, the guilt offering, the gift of the shoulders, the sacrifice of sanctification, and the first fruits of the holy things. 32 Stretch out your hand to the poor, so that your blessing may be complete. 33 Give graciously to all the living; do not withhold kindness even from the dead.

Date: 195-175 B.C.E.
* Dates are based on scholarly estimates

Didache 13:3

1 But every true prophet who wishes to settle among you is worthy of his food. 2 Likewise a true teacher is himself worthy, like the workman, of his food. 3 Therefore thou shalt take the firstfruit of the produce of the winepress and of the threshingfloor and of oxen and sheep, and shalt give them as the firstfruits to the prophets, for they are your high priests. 4 But if you have not a prophet, give to the poor. 5 If thou makest bread, take the firstfruits, and give it according to the commandment.

Date: 50-70 C.E.
* Dates are based on scholarly estimates