The command says,
“Neither shall you give false testimony against your neighbor.” Deuteronomy 5:20
Note that this command is specifically about giving false testimony about your neighbor. This includes gossip. It is also only directed toward a neighbor. Who is your neighbor is another whole study, but basically it is anyone who behaves as a Christian toward you and others.
It is never wrong to deceive or lie to or about one who hates our God to save health or innocent life.