Georg Autenrieth, A Homeric Dictionary

ἐν, ἐνί, εἰν, εἰνί : in.—I. adv., in, therein, among them, Il. 5.740, etc.; esp. the form ἔνι, for ἔνεστι, ἔνεισι, πολέες δ᾽ ἔνι μῦθοι, Il. 20.248. Here belong all examples of ‘tmesis’ so-called, ἐν δ᾽ ἔπεσε, ‘fell on’ the throng, Il. 15.624. The adv. may be defined in its relation by a dative in the same clause, thus showing an approach to the true prepositional use, ἐν δέ τε θυ_μὸς στήθεσιν ἄτρομός ἐστιν, in them, viz., in their breasts, Il. 16.162.—II. prep. w. dat., in, on, among; not only of place and persons, ἐν Δαναοῖσι, ἐν α?θανάτοισι, ἐνὶ στρατῷ, ἐν πᾶσιν, Od. 2.194; but also of conditions, physical and mental, ἐν φιλότητι, ἐν πένθεϊ, ἐν δοιῇ, Il. 9.230. Of time, ὥρῃ ἐν εἰαρινῇ, Π 643, Od. 18.367; instead of a causal or an instrumental expression, ἐν ὀφθαλμοῖς ὁρᾶν, Il. 1.587, Il. 3.306, Od. 10.385; κατακτείνεσθαι ἀνδρῶν ἐν παλάμῃσιν, Ε 558, Il. 24.738, etc.; often with verbs of motion, the state of rest after motion taking the place of movement into, ἐν γούνασι πι?πτειν, Il. 5.370; ἐν χερσὶ τιθέναι, etc.; elliptical, ἐνὶ Κίρκης, sc. ὄικῳ, Od. 10.282, esp. εἰν Ἀίδα_ο. When ἐνί follows its case, it is written ἔνι (‘anastrophe’), Il. 9.53.