But you, when your turn in the action comes, be strong. When she cries 'Son!' cry out 'My father's son!' Go through with the murder—innocent at last. (lines 827–830)

The chorus speaks these words in their last ode before the climax of the play. After praying to Zeus, the household gods, Apollo and Hermes, the chorus addresses Orestes (figuratively, not literally.) Anticipating Clytamnestra's emotional hold over her son, the chorus warns him that when she appeals to him as a mother, he should deny his bond to her and call himself Agamemnon's son only. This way, he will not really be guilty of matricide, as Clytamnestra has been discredited as his mother. Since Clytamnestra has taken on the attributes of a man and violated the safety of the home, she no longer has a right to the privileges of a mother and deserves to die like a man.

This quote also reflects the chorus's naiveté regarding the outcome of Orestes's actions. They engage in the same kind of wishful thinking for which they criticized Orestes and Electra after the kommos. We will soon discover that the Furies do not consider Orestes to be innocent at all.