Tradition
St. John Chrysostom
Homilies on the Gospel of John
Homily 77 › John 15:21
“But all these things will they do unto you for My Name's sake, because they know not Him that sent Me.”
That is, “they insult Him also.” Besides this, depriving those others of excuse, and putting also another source of comfort, He says,
Source: Homilies on the Gospel of John (New Advent)