Original guru

 When Lord Krishna appeared in Navadvipa as Lord Chaitanya, Lord Balarama joined Him incarnating as Lord Nityananda. Chaitanya Mahaprabhu cannot be approached or understood without the mercy of Nityananda Prabhu, who is the original guru of all the universes and serves as an intermediary between Mahaprabhu and His devotees.

His mercy knew no bounds, and people fortunate to come in contact with Him were inundated with love of Godhead. It was by His mercy that Raghunatha dasa, one of the six Goswamis, started the famous Danda Mahotsava festival of Panihati (a tradition that continues to this day) and was thus able to serve Chaitanya Mahaprabhu.

When Nityananda Prabhu came across the Jagai and Madhai brothers, their life was sinful - illicit sex, intoxication, meat-eating, and gambling - though they were born in a nice brahmana family. Once these two brothers were creating disturbance on the street, Lord Nityananda and Haridasa Thakura were out for preaching. So people informed them.  Nityananda Prabhu said, "Why not deliver these two brothers immediately? Then it will be a great credit for Chaitanya Mahaprabhu." The Jagai-Madhai brothers hurt Him on the head by throwing a stone and Nityananda Prabhu started bleeding. 

On coming to know about it Lord Chaitanya Mahaprabhu became very angry: "I shall kill these two brothers immediately.”  Nityananda Prabhu entreated, "You wanted to deliver poor souls. So don't kill them. Accept them." This is Nityananda Prabhu's business, guru's business. The brothers in the meantime fell down at the lotus feet of Lord Chaitanya, "We are so sinful. We have done wrong. Kindly excuse us."