Adam Clarke on Exodus 20:16

Thou shalt not bear false witness, etc. - Not only false oaths, to deprive a man of his life or of his right, are here prohibited, but all whispering, tale-bearing, slander, and calumny; in a word, whatever is deposed as a truth, which is false in fact, and tends to injure another in his goods, person, or character, is against the spirit and letter of this law. Suppressing the truth when known, by which a person may be defrauded of his property or his good name, or lie under injuries or disabilities which a discovery of the truth would have prevented, is also a crime against this law. He who bears a false testimony against or belies even the devil himself, comes under the curse of this law, because his testimony is false. By the term neighbor any human being is intended, whether he rank among our enemies or friends.