John 16:26

At that day As in John 16:23 and John 14:20 from Pentecost onwards.

ye shall ask in my name With the perfect knowledge just promised they will discern what may be asked in His name (see on John 14:13): - cognitio parit orationem."

I say not unto you This does not mean -I need not say unto you; for of course I shall do so;" which does not harmonize with John 16:27. The meaning rather is, that so long as through the power of the Advocate they have direct communion with the Father in Christ's name, there is no need to speak of Christ's intercession. But this communion may be interrupted by sin, and then Christ becomes their Advocate (1 John 2:1; Romans 8:34).

that I will pray The pronoun is emphatic. On the word here rendered -pray" (erôtân) see on John 14:16.

for you More literally, concerning you.