Srimad Bhagavatam Canto 03, Chapter 19, Text 15

SB 3.19.15

vrkne sva-sule bahudharina hareh
 pratyetya vistirnam uro vibhutimat
pravrddha-rosah sa kathora-mustina
 nadan prahrtyantaradhiyatasurah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The demon was enraged when his trident was cut to pieces by the discus of the Personality of Godhead. He therefore advanced toward the Lord and, roaring aloud, struck his hard fist against the Lord’s broad chest, which bore the mark of Srivatsa. Then he went out of sight.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Srivatsa is a curl of white hair on the chest of the Lord which is a special sign of His being the Supreme Personality of Godhead. In Vaikunthaloka or in Goloka Vrndavana, the inhabitants are exactly of the same form as the Personality of Godhead, but by this Srivatsa mark on the chest of the Lord He is distinguished from all others.
Srimad Bhagavatam Canto 03, Chapter 19, Text 14
Srimad Bhagavatam Canto 03, Chapter 19, Text 16