A.T. Robertson Commentary John 16:4

"But these things have I spoken unto you, that when their hour is come, ye may remember them, how that I told you. And these things I said not unto you from the beginning, because I was with you." — John 16:4 (ASV)

Have I spoken (λελαληκα). Perfect active indicative as in 15:11; 16:1. Solemn repetition.

When their hour is come (οταν ελθη η ωρα αυτων). Indefinite temporal clause, οταν with the second aorist active subjunctive of ερχομα, "whenever their hour comes." The time appointed for these things.

Now that (οτ). Simply "that" (declarative conjunction in indirect discourse. Forewarned is to be forearmed. Cf. 13:19.

From the beginning (εξ αρχης). As in 6:64 but practically like απ' αρχης in 15:27. While Christ was with them, he was the object of attack (15:18).