George Haydock's Catholic Commentary
Psalms 88:31
And if. God foresaw the prevarications of the Israelites and Christians: But he speaks this to shew their free-will, and that he would treat them as children, (Berthier) and not with the utmost severity, (Calmet) unless they proved obstinate, 2 Kings vii. 14. (Haydock) --- Some shall always continue faithful, and shall be glorified, while the bad shall be cast away. (St. Augustine) --- Christ will never lose his Church. (Worthington)