LXX Deut 14:28

καὶ ἐλεύσεται ὁ Λευείτης, ὅτι οὐκ ἔστιν αὐτῷ μερὶς οὐδὲ κλῆρος μετὰ σοῦ, καὶ ὁ προσήλυτος καὶ ὁ ὀρφανὸς κα ἡ χήρα ἡ ἱέν ταῖς πόλεσιν σου, καὶ φάγονται καὶ ἐμπλησθήσονται, ἵνα εὐλογήσῃ σε κύριος ὁ θεός σου ἐν πᾶσιν τοῖς ἔργοις οἷς ἐὰν ποιῇς.

At the end of every three years, bring a tenth of all your produce for that year and lay it up within your gates.