That ye endure (υπομενετε). Present active indicative or present active imperative and so just "endure for chastening."

Dealeth with you (υμιν προσφερετα). Present middle indicative of προσφερω, but this sense of bearing oneself towards one with the dative here only in the N.T., though often in the older Greek.

What (τις). Interrogative.

Whom (ον). Relative. Cf. Matthew 7:9.