In many questions asked on this site, I frequently see a line about Vishnu teaching principles of Vaishnavism to his four disciples:
Vishnu is said to have taught the principles of Vaishnavism to four disciples: Lakshmi, Brahma, Shiva and Sanatkumara. And in turn they started the four main Sampradayas or traditions of Vaishnavism: Sri Sampradayam, Brahma Sampradayam, Rudra Sampradayam, and Kumara Sampradayam.
So, I want to know which scriptures mention this thing? I know it's not mentioned in Valmiki Ramayana and Mahabharata of Vyasa. Neither it's mentioned in Srimad Bhagavata, Vishnu and Padma Purana as far as I know There is possibility that it's mentioned in other Puranas like Varaha and Narada.
Most probably it's mentioned in Pancharatra Agamas. If it's mentioned, I want to know which Samhita and Chapter of Pancharatra Agamas mention it? Also when did Lord Vishnu do this teaching?