Why did Paul say he could wish himself accursed from Christ for his brethren?

Paul declared he could wish himself accursed from Christ because of his love for the Jew, his brethren. He carried great heaviness and continual sorrow in his heart for them, and he was willing to be cut off if it would help Israel, comparable to Moses offering to be blotted out to spare the people.

Les teaches that in Romans 9, Paul is entering a parenthetical section where he sets aside instructions and doctrines for Gentiles and deals with the nation of Israel for three chapters—past, present, and future. Paul begins by saying he tells the truth in Christ, with his conscience bearing witness in the Holy Spirit, that he has great heaviness and continual sorrow in his heart. He could wish himself accursed from Christ because of his love for the Jew. Les compares this to Moses, who asked God to spare the people and, if it would help, blot his name out of the book of life, but spare Israel.

Romans 9:1

I say the truth in Christ, I lie not, my conscience also bearing me witness in the Holy Ghost,

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Who else said almost the same thing as Paul when he wished himself accursed from Christ?

Moses said almost the same thing. Like Paul's willingness to be accursed from Christ for Israel's sake, Moses asked God to spare the people and, if it would help, to blot his name out of the book of life rather than fail to spare Israel.