Why is the relative pronoun put in the dative case? why feminine? (Greek)

Question

I was a little stumped, here, when I came across the feminine relative pronoun ᾗ.

ἴσως δή, εἶπον, παρὰ τὸ ἔθος γελοῖα ἂν φαίνοιτο πολλὰ περὶ τὰ νῦν λεγόμενα, εἰ πράξεται ᾗ λέγεται.

καὶ μάλα, ἔφη.

Plato's Republic, Book 5, section 452a

Here's how I translated the passage:

"Perhaps then," I said, "being contrary to custom, many things related to what we're saying should seem ridiculous, if they will be done according to what is said."

"Yes," he said.

First, I'm unsure as to why ᾗ is in the feminine singular. Is this an arbitrary choice? Or is there a logic to it? For several reasons, I would expect the neuter instead of the feminine.

Second, why the dative case? Nominative makes more sense to me. Is there a better way to translate the dative than the one I gave?

I think the best translation would be, "if what is said will be done", but this would be more liberal, and I wanted to understand how the nuts and bolts worked first.

Answer 1

This is an adverbial use of the relative and has its own entry in LSJ. It's used in comparative clauses, for example.

LSJ:

ᾗ, dat. sg. fem. of relat. Pron. ὅς, ἥ, ὅ, in adverb. sense ... II. of Manner, how, as.

Smyth (§2463):

Comparative clauses of quality or manner are introduced by ὡς as, ὥσπερ, καθάπερ just as, ὅπως, ᾗ, ὅπῃ, ᾗπερ as