Jesus uses a singular form of address here, You blind Pharisee! but he is surely addressing all of them as a group, not just one individual. Most translators will retain the singular form, unless readers will then only understand the sentence to be addressed to one person. Then they can use “You blind people, you Pharisees” or “You are so blind, you Pharisees.”

The cup and plate may be understood figuratively of the Pharisees, in which case first cleanse the inside of the cup and of the plate may be translated “Give attention first of all to inner purity, then everything outside will also be pure” (Die Bibel im heutigen Deutsch). On the other hand, if the cup and plate are understood in a nonfigurative sense, then there is no need to remove the imagery from the translation. Translators can say “First be sure that what is inside the cup and plate is clean.”

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .