This refers to a wall that was painted white to make it look clean. Paul told Ananias that just as a wall can be painted to look clean so Ananias appeared to look morally clean, but he was really full of evil intent. Alternate translation: "white-painted wall" or "wall painted white" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Paul uses a question to point out Ananias' hypocrisy. Alternate translation: "You sit there to judge ... against the law." (See: [[rc://en/ta/man/translate/figs-rquestion]])
This can be stated in active form. You can use the same word for "strike" as you did in the phrase "God will strike you." Alternate translation: "command people to strike me" (See: [[rc://en/ta/man/translate/figs-activepassive]])