John Gill Commentary Proverbs 3:30

"Strive not with a man without cause, If he have done thee no harm." — Proverbs 3:30 (ASV)

Strive not with a man without cause ,
Either by words, in a wrangling, quarrelsome, and contentious way, for mere trifles; when there is no foundation for it, no just reason given to form a complaint, or pick a quarrel upon; or by deeds, by lawsuits, when there is nothing to proceed upon; or it is so trifling, that it is not worth while to litigate it or contend about: such, who strive either way, are far from following the example of Wisdom or Christ, and from taking his advice, (Matthew 12:19) (5:40) ;

if he has done you no harm ;
no real hurt to your person, nor injury to your substance; if he has not abused nor defrauded you, nor taken any thing from you by force or fraud, nor withheld from you what is your right and due. But otherwise the laws of God and man ought to take place; right may be sought for, and justice should be done.