EXOD630 Shlomo, a"h, said (Mishlei 24:28-29), "Do not be a witness needlessly against your fellowman, and grind [him] with your lips. Do not say, 'As he has done to me I will do to him; I will repay the man according to his work.'" The explanation is [as follows]:[Shlomo] did not need to admonish, "Do not be a false witness"; rather, he said, "Do not be a witness needlessly'--if your fellowman succumbs to sin, you should neither testify against him nor expose his sin, needlessly, i.e., without reproving him. True, if he has stolen from another or cheated a person, one is obligated to bear witness regarding this in order that he return the theft, based upon the testimony of two witnesses; and if there is only one witness, an oath shall be taken between them [this verse; i.e., if the situation concerns torts, damages, and other monetary claims, one is obligated to testify; see Shulchan Aruch, Choshen Mishpat 28:1. Even one witness in such cases can force an oath in order to effect restitution. See paragraph 221 that even in this case, he must first try to reform the sinner through reproof]. But if one sees that his fellowman has stumbled in [a sin] of immorality [Devarim 24:1], or another such sin, he should not testify needlessly, i.e., without reproving the other, even if the observer has another witness who together with him will establish the facts [Rabbeinu Yonah is referring to a situation where the testimony can serve no purpose other than bringing the sinner to repent. See Chafetz Chayim, Hilchos Lashon Hara 4:4]. (Continued at [GEN296]] Genesis 2:18 alone GATES 422-3).