For the dative of purpose (
ἐκείνῳ ἡ χώρα_ δῶρον ἐδόθη
ἧλοι ταῖς θύραις
a. The infinitive was originally, at least in part, a dative of an abstract substantive, and served to mark purpose: τίς τ' ἄρ σφωε θεῶν ἔριδι ξυνέηκε μάχεσθαι; who then of the gods brought the twain together (for) to contend in strife? A 8. Cp. “what went ye out for to see?” St. Matth. 11. 8.
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].