I'm sure it's Matthew 5:22 ...
The Bible allows for righteous anger, as opposed to sinful anger. My anger is righteous. Jesus himself showed righteous anger: "He looked around at them in anger and, deeply distressed at their stubborn hearts, said to the man, “Stretch out your hand.” He stretched it out, and his hand was completely restored." - Mark, 3:5
However, Jesus does condemn hypocrites: "Jesus addressed the other form of hypocrisy in the Sermon on the Mount: “Why do you look at the speck of sawdust in your brother’s eye and pay no attention to the plank in your own eye? How can you say to your brother, ‘Let me take the speck out of your eye,’ when all the time there is a plank in your own eye? You hypocrite, first take the plank out of your own eye, and then you will see clearly to remove the speck from your brother’s eye” (Matthew 7:3-5).