Be ye angry and sin not (orgizesqe kai mh amartanete). Permissive imperative, not a command to be angry. Prohibition against sinning as the peril in anger. Quotation from Psalms 4:4 . Let not the sun go down upon your wrath (o hlio mh epiduetw epi parorgismwi). Danger in settled mood of anger. Parorgismo (provocation), from parorgizw, to exasperate to anger, occurs only in LXX and here in N.T.