John Stott on Psalm 42-43

...Each stanza concludes with the same refrain (42:5, 11; 43:5). In it the psalmist speaks to himself. Talking to oneself is popularly said to be the first sign of madness. But on the contrary, it is a sure sign of maturity--though depending on what we are talking to ourselves about! Here the psalmist refuses to acquiesce in his condition or give into his moods. He takes himself in hand. Firstly, he questions himself: "Why are you downcast, O my soul?" His question includes an implied rebuke. Secondly, he exhorts himself: "Put your hope in God." For God is worthy of our trust. Thirdly, he assures himself: "For I will yet praise him, my Savior and my God." His double use of the personal possessive "my Savior and my God" is highly significant. He is reminding himself of his covenant relationship with God, which no fluctuating moods can ever destroy. --John Stott