In Rom. 12:10, the Greek text states,
τῇ φιλαδελφίᾳ εἰς ἀλλήλους φιλόστοργοι τῇ τιμῇ ἀλλήλους προηγούμενοι TR, 1550
There are essentially two clauses in Rom. 12:10:
- τῇ φιλαδελφίᾳ εἰς ἀλλήλους φιλόστοργοι
- τῇ τιμῇ ἀλλήλους προηγούμενοι
According to Tischendorf, there are no relevant textual variants.1
In the second clause, we may supply the preposition «εἰς» ("to"), omitted by ellipsis, between «τιμῇ» and «ἀλλήλους».
Regarding both «τῇ φιλαδελφίᾳ» and «τῇ τιμῇ» which are declined in the dative case, the dative is likely a dative of reference/respect and may be translated as "Respecting2 brotherly love" and "Respecting honor," respectively.
George Benedikt Winer wrote,3
The clauses lack verbs; the imperative verb «ἔστε» ("be") may be supplied. Accordingly, the adjective «φιλόστοργοι» would function as a predicate adjective, while the participle «προηγούμενοι» would function substantively as a predicate nominative.
Therefore, the verse may be translated as,
Regarding brotherly love, be affectionate to one another. Regarding honor,4 be guides to one another.
Footnotes
1 p. 431
2 or "regarding"; "as pertaining to"
3 p. 215
4 i.e., respect and dignity displayed to fellow humans. They are to set the example on how to treat others with dignity and respect, thereby being guides for others to follow.
References
Tischendorf, Constantin. Novum Testamentum Graece. Vol. 2. Lipsiae: Giesecke, 1872.
Winer, George Benedikt. A Grammar of the Idiom of the New Testament. 7th ed. Andover: Draper, 1892.