1. Question Restatement:
In 2 Corinthians 6:14 - What does "Unequally Yoked" together mean?
Are there any Scriptural or Literary Greek examples where the context clarifies the meaning of the metaphor?
2. Answer - A "Yoke-Fellow", "Equal Partnership", or "Ally":
When Involving People - a "Yoke-Fellow" is a Metaphor for an "Alliance" or "Equal Partnership" :
1 Maccabees 1:15 - They had surgery performed to hide their circumcision, abandoned the holy covenant, started associating, (ἐζευγίσθησαν, LXX) with Gentiles, and did all sorts of other evil things.
Plutarch, Cimon 16:8 - And Ion actually mentions the phrase by which, more than by anything else, Cimon prevailed upon the Athenians, exhorting them “not to suffer Hellas to be crippled, nor their city to be robbed of its yoke-fellow.”
ὁ δ’ Ἴων ἀπομνημονεύει καὶ τὸν λόγον, ᾧ μάλιστα τοὺς Ἀθηναίους ἐκίνησε, παρακαλῶν μήτε τὴν Ἑλλάδα χωλὴν μήτε τὴν πόλιν ἑτερόζυγα περιϊδεῖν γεγενημένην.
And, in Context: Paul is clearly addressing "Holiness", and "Separation" :
NASB, 2 Corinthians 6:17 - “Therefore, come out from their midst and be separate,” says the Lord.
NASB, 2 Corinthians 7:1 - Therefore, having these promises, beloved, let us cleanse ourselves from all defilement of flesh and spirit, perfecting holiness in the fear of God.
3. The Context Affirms a Sense of Partnership:
In this context - the sense being conveyed are "Balanced" and "Equal" "Partnerships", in both: obligations and rewards.
To Substantiate his Instruction - Paul employs a Syllogistic Argument to prove there can be no confidence in a partnership with the World:
Paraphrase, 2 Corinthians 6:14-6 - Do not be partnered with unbelievers;
- for what share is there: for the just and lawless?
- or what intimacy is there: light towards darkness?
- and what agreement is there: has Christ towards Belial?
- or what portion is there: for a believer together with an unbeliever?
- and what consensus is there: for the temple of God together with idols?
2 Corinthians 6:17 - THEREFORE, [if those premises are valid], come out of their midst - and be separate.
Which is a reference to Isaiah:
NKJV, Isaiah 52:11 - Depart! Depart! Go out from there, Touch no unclean thing; Go out from the midst of her, Be clean, You who bear the vessels of the Lord. (cf. NKJV, 2 Corinthians 6:17.)
Paul explicitly points out that existing marriages are an exception to Rule #4, (above) :
NASB, 1 Corinthians 7:16 - For how do you know, O wife, whether you will save your husband? Or how do you know, O husband, whether you will save your wife?
Note: As in Scripture, it also seems there are no examples in Literary Greek where "Yoke-Fellow" appears in the context of "Marriage".
4. Analysis of the Greek:
The Greek construction is consistently used - in Scripture and Literary Greek - and always indicates: a consistent, balanced, standard applied to all parties, whether in obligations or rewards.
This is true in contexts regarding beasts of burden, chariots with teams of horses, and partnerships between people.
Analysis of "ἑτεροζυγοῦντες", "ἑτερόζυξ" :
ἑτερο- from ἕτερος, (Logeion Lexicon) - Does not denote: "inequality" - but rather an "other", a different referent. Someone else, another animal, etc.
-ζυγοῦντες, related to ζυγέω, ζυγή, ζεύγνυμι, etc - In the most abstract sense, denotes: a standard, a consistent measure, an equal load upon participants, (whether animals or people), a merchant's scale, an equal measurement, an equal pair; when involving people - an equal partnership, an alliance.
Prohibition Against Mixing Breeds under a Yoke :
Note : This seems to be a prohibition even against selective breeding - not just mating between species.
Septuagint, Leviticus 19:19 - ... You shall not crossbreed pairs | ἑτεροζύγῳ of animals, you shall not sow your field with two kinds of seed;
Joseph. AJ 4.228 - You are to plough your land with oxen, and not to oblige other animals to come under the same yoke | αὐτοῖς ὑπὸ ζεύγλην with them; but to till your land with those beasts that are of the same kind with each other.
Josephus May be Applying the Rule Among People as well:
ibid. ... - for there is reason to fear that this unnatural abuse may extend from beasts of different kinds - to men.
A "Consistent Standard", or "Rule of Law" :
Katabiblon, LXX, Zephaniah 3:9 - Because I will transform the peoples language into the same form that all may call upon the name of the Lord obeying Him under one scale, (standard) | ὑπὸ ζυγὸν ἕνα;
Teams of Animals - Necessitating Equal Performance :
Andocides, Speeches 4:26 - What would he have done, may we ask, had one of your allies arrived with a team [of horses] | ζεῦγος ἵππων?