Charak Samhita
चिकित्सति भिषक् सर्वास्त्रिकाला वेदना इति। यया युक्त्या वदन्त्येके सा युक्तिरुपधार्यताम् ॥८६॥
The following logic is given here while responding to the question on the management of illnesses of the past, the present and the future.
english translation
cikitsati bhiSak sarvAstrikAlA vedanA iti। yayA yuktyA vadantyeke sA yuktirupadhAryatAm ॥86॥
hk transliteration by Sanscript