▼ The article τῆς (tēs) has been translated as a possessive pronoun, “your” (ExSyn 215). It may also be functioning to indicate a well-known concept (inheritance as eternal life). See BDAG 548 s.v. κληρονομία 3: “common in Christian usage (corresp. to the LXX) (the possession of) transcendent salvation (as the inheritance of God’s children).”

▼ The genitive τῆς κληρονομίας (tēs klēronomias) is a genitive of apposition: The reward consists of the inheritance.

▼ The form of the term δουλεύετε (douleuete) is ambiguous; it can be read as either indicative or imperative. In favor of the indicative: (1) it seems to explain better the first part of v. 24, esp. “from the Lord” which would then read as: “because you know that you will receive your inheritance from the Lord as a reward for it is the Lord you are serving.” The “for” is supplied to make the relation explicit (it is actually added in many mss - D¹ Ψ 075 Maj. - but the best ms evidence is against its inclusion). (2) With the imperative, one might expect ὡς τῷ κυρίῳ (hōs tō kuriō), as for example in Eph 6:7. In favor of the imperative: (1) an imperative resumes the ἐργάζεσθε (ergazesqe) in v. 23a and forms a chiasm with it; (2) an imperative makes more sense of the γάρ (gar) in v. 25a; (3) an imperative relates equally well to the preceding statement; (4) a parallel can be found in Rom 12:11 which uses an imperatival participle δουλεύοντες (douleuontes) with the dative τῷ κυρίῳ. For an elaboration of these points see M. J. Harris, Colossians and Philemon (EGGNT), 185–86.