Gregory the Great
Catena Aurea · Johannesevangelium 15
This is my commandment, That ye love one another, as I have loved you. Greater love hath no man than this, that a man lay down his life for his friends. Ye are my friends, if ye do whatsoever I command you. Henceforth I call you not servants; for the servant knoweth not what his Lord doeth: but I have called you friends; for all things that I have heard of my Father I have made known unto you. Ye have not chosen me, but I have chosen you, and ordained you, that ye should go and bring forth fruit, and that your fruit should remain: that whatsoever ye shall ask of the Father in my name, he may give it you. But I have called you friends, for all things that I have heard of My Father, I have made known unto you.
(Hom. xxvii.) Or all things which He heard from the Father, which He wished to be made known to His servants; the joys of spiritual love, the pleasures of our heavenly country, which He impresses daily on our minds by the inspiration of His love. For while we love the heavenly things we hear, we know them by loving, because love is itself knowledge. He had made all things known to them then, because being withdrawn from earthly desires, they burned with the fire of divine love.