of his fulness - of “grace and truth,” resuming the thread of Joh 1:14.
grace for grace - that is, grace upon grace (so all the best interpreters), in successive communications and larger measures, as each was able to take it in. Observe, the word “truth” is here dropped. “Grace” being the chosen New Testament word for the whole fullness of the new covenant, all that dwells in Christ for men.