John 14:20 — ExegesisTAB

The temporal frame en ekeinē tē hēmera {ἐν ἐκείνῃ τῇ ἡμέρᾳ | en ekeinē tē hēmera} ‘in that day’ places the promise in a definite future moment of disclosure. The future middle gnōsesthe {γνώσεσθε | gnṓ-se-sthe} ‘you will know’ presents knowledge as something the disciples themselves will enter into, not merely receive as detached information. The content of that knowledge is introduced by hoti {ὅτι | hó-ti} ‘that’, followed by a series of tightly balanced clauses. The first clause, egō en tō patri mou {ἐγὼ ἐν τῷ πατρί μου | e-gō en tō patri mou}, is verbless in Greek and relies on en {ἐν | en} to express relational indwelling rather than ordinary location. The possessive mou {μου | mou} keeps the Father-Son relation explicit. The next pair of clauses, kai hymeis en emoi kagō en hymin {καὶ ὑμεῖς ἐν ἐμοὶ κἀγὼ ἐν ὑμῖν | kai hymeis en emoi kagō en hymin}, mirrors the first clause and creates a symmetrical pattern of mutual indwelling. The compressed form kagō {κἀγώ | ka-gō} preserves the final balance and binds the last clause back to the first, so the whole sentence reads as a three-part reciprocity: the Son in the Father, the disciples in the Son, and the Son in the disciples. English renderings that keep repeated “in” language or use “within” preserve this theological symmetry most clearly.