The Compendium of Caraka 2.1.17

2.1.17

Now indeed, fever arises in human beings from eight causes; that is to say: from vāta, from pitta, from kapha, from vāta and pitta, from vāta and kapha, from pitta and kapha, from vāta, pitta, and kapha, and from an exogenous [factor] as the eighth cause.