Charak Samhita
नियतस्त्वनुबन्धो रजस्तमसोः परस्परं, न ह्यरजस्कं तमः प्रवर्तते ॥९॥
[Psychic doshas- their eternal union] There is an eternal union between the two dosha pertaining to mind, viz. rajas and tamas. Tamas cannot manifest its actions without rajas.
english translation
नियतस्त्वनुबन्धो रजस्तमसोः परस्परं, न ह्यरजस्कं तमः प्रवर्तते ॥९॥
[Psychic doshas- their eternal union] There is an eternal union between the two dosha pertaining to mind, viz. rajas and tamas. Tamas cannot manifest its actions without rajas.
english translation