The 285th prohibition is that we are forbidden from giving false testimony.

The source of this prohibition is G‑d's statement,1 "Do not testify as a false witness (eid sheker) against your neighbor." This prohibition is repeated using a different expression,2 "as a perjurous witness" (eid shav).

Scripture3 dictates the punishment for one who violates this prohibition, "You must do the same to them as they plotted to do to their brother." The Mechilta says,4 "The verse, 'Do not testify as a false witness' is the prohibition regarding false witnesses (eidim zom'mim5)"

The punishment for violating this prohibition is lashes, as explained in the last chapter6 of tractate Makkos, where the details of this mitzvah are explained.