καὶ δᾶν] Best taken separately, as in ver. 19; ‘and if,’ ‘although.

φοινικοῦν...κόκκινον...λευκανῶ] Cf. Ps. li. 7. If scarlet or crimson is not elsewhere used (see Skinner's note on this verse) to suggest sin, ver. 15, ‘full of blood,’ accounts for it here. At any rate, the intense colour contrasts with the white robes of purity. See Rev. xvii. 4: but there is one Blood which whitens (Rev. vii. 14).

ἔριον] Cf. Dan. vii. 9. Wool was most carefully bleached in ancient times, and so forms a parallel to snow: Virg. Georg. III. 391 “munere niveo lanae’

19. ἐὰν θέλητε] Cf. Matt. xxiii. 37, ποσάκις ἠθελήσα...καὶ οὐκ ἠθελήσατε φάγεσθε] φάγομαι is constantly used as a future form in LXX., and in N.T., as Luke xiv. 15.

21. Σιὼν] Not in the Heb.; perhaps added here from ver. 26.