भगवान बुद्ध ने सारनाथ के प्रथम उपदेश में क्या कहा था, Buddha gave his first sermon on Guru Purnima:

Guru Purnima, a day meant for paying an ode to teachers and mentors in India, is observed on the Purnima Tithi (full Moon night) in the month of Ashadha as per the Purnimant calendar.
Teachings from Gautam Buddha's first sermon : Four Noble truths, Ariya Aṭṭhaṅgika Magga