Sahih Muslim Book 32, Hadith Number 6327.
Chapter : Grim warning to one who torments people without any valid justification.
‘Urwa reported on the authority of his father that Hisham b. Hakim b. Hizam happened to pass by some people in Syria who had been made to stand in the sun and olive-oil was being poured upon their heads. He said: What is this? It was said: They are being punished for (not paying) the Kharaj (the government revenue). Thereupon he said: Allah would punish those who torment people in this world (without any genuine reason).