If I had said "I will speak thus", I would have betrayed the generation of your children.
In context, this verse in Psalm 73 is saying something pretty controversial in today's world (and church). The Psalmist had big doubts about the goodness of God, and he kept them to himself. And looking back, he is glad he kept them to himself. His doubts could have damaged other people.
I'm all for honesty, and I'm absolutely committed to the idea that the church is a community which accepts doubters, and doesn't discourage openness about struggles with faith. But I do wonder whether sometimes 'personal integrity' is viewed as an ultimate good. I think this, so I have to say it. I doubt this, so I'd best express that. This Psalm suggests that sometimes it would be better to have internal anguish rather than cause others to suffer.
I just thought that was interesting in a world where everyone has to 'be themselves', and a church where contradicting centuries of Christian teaching and belief is applauded as heroic so long as you are doing it for the sake of integrity.