Adam Clarke on John 15:3

Now ye are clean - Καθαροι εστε, Ye are pruned. As our Lord has not changed the metaphor, it would be wrong to change the expression.

Through the word - Δια τον λογον, Through that word - that doctrine of holiness which I have incessantly preached unto you, and which ye have received. Perhaps our Lord more immediately refers here to the words which he had spoken concerning Judas, Joh 13:21-30, in consequence of which Judas went out and finished his bargain with the chief priests; he being gone off, the body of the apostles was purified; and thus he might say, Now ye are clean through the word which I have spoken unto you.