John 15:14-15
“You are My friends —henceforth I call you not servants, for the servant knows not what his lord does. You are My friends, for all things which I have heard of My Father I have made known unto you.”
How then says He, “I have many things to tell you, but you cannot bear them now”? By the “all” and the “hearing” He shows nothing else, but that He uttered nothing alien, but only what was of the Father. And since to speak of secrets appears to be the strongest proof of friendship, “you have,” He says, “been deemed worthy even of this communion.” When however He says “all,” He means, “whatever things it was fit that they should hear.” Then He puts also another sure proof of friendship, no common one. Of what sort was that?
Source: Homilies on the Gospel of John (New Advent)