Henceforth I call you not servants - that is, in the sense explained in the next words; for servants He still calls them (Joh 15:20), and they delight to call themselves so, in the sense of being “under law to Christ” (1Co 9:20).
the servant knoweth not what his lord doeth - knows nothing of his master’s plans and reasons, but simply receives and executes his orders.
but ... friends, for all things that I have heard of my Father I have made known unto you - admitted you to free, unrestrained fellowship, keeping back nothing from you which I have received to communicate. (Compare Gen 18:17; Psa 25:14; Isa 50:4).