Charak Samhita
पूर्वरूपं भिषग्बुद्ध्वा व्रणानां शोफमादितः । रक्तावसेचनं कुर्यादजातव्रणशान्तये ॥४४॥
॥ Guidelines for management of ulcers॥ The physician observing shopha (swelling) as prodromal sign in the beginning should apply blood-letting to prevent the manifestation of wound.
english translation
pUrvarUpaM bhiSagbuddhvA vraNAnAM zophamAditaH । raktAvasecanaM kuryAdajAtavraNazAntaye ॥44॥
hk transliteration by Sanscript