Psalm 101:5

“For if persecution could not be done rightly, it had not been said in a certain Psalm, “Whoso privily slandereth his neighbour, him did I persecute.”…Let none then say, I suffer persecution: let him not sift the punishment, but prove the cause: lest if he prove not the cause, he be numbered with the ungodly.” — editor's note: Ps. ci. 5.

““Whoso privily slandered his neighbour, him I persecuted” (ver. 5).” — the author cites it