The Compendium of Caraka 1.1.24

1.1.24

hetuliṅgauṣadhajñānaṃ svasthāturaparāyaṇam /
trisūtraṃ śāśvataṃ puṇyaṃ bubudhe yaṃ pitāmahaḥ //

the knowledge of etiology, symptoms, and therapeutics, the supreme recourse of both the healthy and the sick,
the eternal, auspicious triad of aphorisms that the Grandfather knew.