LXX Deuteronomy 18:4
2 And they shall have no inheritance among their brethren; the Lord himself is his portion, as he said to him. 3 And this is the due of the priests in the things coming from the people from those who offer sacrifices, whether it be a calf or a sheep; and thou shalt give the shoulder to the priest, and the cheeks, and the great intestine: 4 and the first-fruits of thy corn, and of thy wine, and of thine oil; and thou shalt give to him the first-fruits of the fleeces of thy sheep: 5 because the Lord has chosen him out of all thy tribes, to stand before the Lord thy God, to minister and bless in his name, himself and his sons among the children of Israel. 6 And if a Levite come from one of the cities of all the children of Israel, where he himself dwells, accordingly as his mind desires, to the place which he shall have chosen,
Didache 13:3
2 Similarly, a genuine teacher is worthy of sustenance, just like any other worker. 3 Therefore, you should offer the first fruits of your wine, grain, oxen, and sheep to the prophets, for they serve as your high priests. 4 If you have no prophets, then give to those in need. 5 When you bake bread, take the first portion and give it in accordance with the commandment. 6 Likewise, when you open a jar of wine or oil, give the first portion to the prophets. 7 With money, clothes, and all your other possessions, take the first portion, and give it as you see fit, in accordance with the commandment.
Notes and References
"... In the light of these various senses of ἀπαρχή ('first fruits') in the Bible and in Hellenistic Jewish texts, and given the fact that the Jewish offerings to the priests and the poor (tithes) were still being made after 70, the complexities of the Jewish-Christian ἀπαρχή ('first fruits') of Didache 13:3-7 become easier to understand. Besides the prescriptions, which are analogous to or in imitation of the Jewish regulations, Didache 13:3-7 mentions not only the traditional agricultural products (corn, wine and oil) and animals (sheep and cattle), but also money, clothing and possessions of every kind (verse 7). The Didache speaks of all these as being κατὰ τὴν ἐντολήν ('according to the commandment'), although the latter categories are not mentioned in the Torah. It appears, however, that the custom of paying the priestly offering and tithes on all possessions - although never really widespread and common in the first century CE (and even later) - was confined to those who were particularly strict and pious Jews and belonged to religious associations. These associations drew their members above all from among the Pharisees, such as the Pharisee of the parable (Luke 18:9-14a) who boasts: “I give a tenth of what I purchase” (verse 12). It is probably they who originated the post-Torah expansions and elaborations of tithing and of other offerings. The Jewish-Christian ἀπαρχή ('first fruits') of Didache 13:7, destined for the prophets or (in their absence) the poor, seems to reflect these Jewish practices ..."
Del Verme, Marcello Didache and Judaism Jewish Roots of an Ancient Christian-Jewish Work (pp. 169-170) T&T Clark International, 2004