Is it permissible to perform Salat al-Gha'ib (funeral prayer in absentia) for someone envious, and is it a condition that he knows about it?

Envy is reprehensible and forbidden in the Quran and Sunnah (definition). It is a blameworthy trait with which Allah condemned the Jews. The Prophet, peace and blessings be upon him, said: "Beware of suspicion, for suspicion is the falsest of speech. And do not spy, nor eavesdrop, nor envy one another, nor turn away from one another, nor hate one another. Be, O servants of Allah, brothers." Faith and envy cannot coexist in the heart of a servant, meaning a believer should not be envious. The envious person is a Muslim, and funeral prayers are offered for him like any other Muslim.