A.T. Robertson Commentary John 16:23

"And in that day ye shall ask me no question. Verily, verily, I say unto you, if ye shall ask anything of the Father, he will give it you in my name." — John 16:23 (ASV)

Ye shall ask me nothing (εμε ουκ ερωτησετε). Either in the sense of question (original meaning of ερωταω) as in verses 19,30 since he will be gone or in the sense of request or favours (like αιτεω in this verse) as in 14:16; Acts 3:2. In verse 26 both αιτεω and ερωταω occur in this sense. Either view makes sense here.

If ye shall ask (αν τ αιτησητε). Third-class condition, αν like εαν with first aorist active subjunctive of αιτεω. Note 14:26 for "in my name."