The standing up of hair on the body was manifested when Mother Yasoda found within Krsna's mouth all of the universal planetary systems. She had asked Krsna to open His mouth wide just to see whether He had eaten dirt. But when Krsna opened His mouth, she saw not only the entire earth, but also many other planets within His mouth. This caused a standing up of the hair on her body.
The standing up of hair on the body resulting from jubilation is described in the Tenth Canto, 30th Chapter, 9th verse of Srimad-Bhagavatam in connection with the gopis engaged in the rasa dance. During this rasa dance Krsna disappeared all of a sudden with Radharani, and the gopis began to search Him out. At that time they addressed the earth and began to say, "My dear earthly planet, how many austerities and penances you must have undergone to have the lotus feet of Krsna always touching your surface. I think that you must be very jubilant because the trees and plants, which are just like hairs on your body, are standing up so gloriously. May we ask when did you first get these symptoms? Are you enjoying this jubilation since you were touched by the incarnation Vamana or since you were delivered by the incarnation Varaha?"
Krsna would sometimes perform mock fighting along with the cowherd boys. When Krsna blew His horn in this mock fighting, Sridama, who was on the opposing side, felt his bodily hairs stand up. Similarly, when Arjuna saw Krsna in His gigantic universal form, there was a standing of the hairs on his body.
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