Maharaj Mandleswar Ji of Haridwaar ((True lover of Guru Nanak)) used to sit with group of sikhs for gurbaani vichaars.... one day a peacock came in the room...In so many people an animals get scared .....however that peacock stood there watching here and there....One person out of that group said to mandleshwar ji that to give some daan to this peacock....and they asked wat to give and he said give him mukat daan (make him free from cycle of death and birth) on which maharaj ji said "In the house of Guru Nanak mukti is not a big thing and mukati is in Guru's bani..... so saadho(sikhs) for this peacock do one Japji Sahib".... And everyone took out there pothis and started reading Japji Sahib...Finally when they reached the last line that is "Nanak Teh mukh Ujaale Keti Chutti naal" that peacock fell down and was no more....(gone to suchkhand)...........
All the sikh touched the feet of Mandaleshwar Ji on which they said "i didn't do that... don't touch my feet... this kirpa is of Japji Sahib....anyone who reads Japji Sahib from heart will become mukaat....."
Hope that make sense....
Bhul Chuuk Maaf
Edit: this happened in between yr 1900-1910(guess)