LXX Deuteronomy 18:4
2 but there shall not be an allotment for them among their brothers; the Lord himself is their allotment, as he said to them. 3 And this is the judgment for the priests, the portions from the people from those offering sacrifices, whether a calf or a sheep; and he shall give the priest the arm and the flesh of the jaw and the fourth stomach of ruminating animals. 4 And the first fruits of your grain and of your wine and of your olive oil, and the first fruits of the fleece of your sheep, you shall give to them. 5 For the Lord chose him from all your tribes to stand before the Lord God to minister and bless in his name, he and his sons among the sons of Israel. 6 “But if a Levite comes from one of the cities of all the sons of Israel, where he dwells as his soul desires, into the place that he may choose,
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