Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 42
Sanskrit:
यथाहं प्रणमे विप्राननुकालं समाहित: ।तथा नमत यूयं च योऽन्यथा मे स दण्डभाक् ॥ ४२ ॥
ITRANS:
yathāhaṁ praṇame viprānanukālaṁ samāhitaḥtathā namata yūyaṁ cayo ’nyathā me sa daṇḍa-bhāk
Translation:
Just us I always carefully bow down to brāhmaṇas, so all of you should likewise bow down to them. I will punish anyone who acts otherwise.