Giving a man 20 lashes for calling him a jew

Is narrated in Tirmidhi, Hadith Number 1024: >The Prophet (peace be upon him) said: "When a man calls another a Jew give him twenty lashes, when he calls someone a mukhannath give him twenty lashes; and kill anyone who has intercourse with a woman who is within the prohibited degrees." What is authenticity of this narration? How to make sense of it exactly if it is authentic.