佛說觀佛三昧海經 1.51

1.51

「云何觀如來額廣平正相？額廣平正相中有三相：一者所謂白毛相。佛初生時，王與夫人將太子詣阿私陀仙，令相太子。仙人披㲲，初見太子眉間白毛旋生，於白毛邊有諸輪郭隨白毛旋，相師舒毛見毛長大，即取尺度量其長短，足滿五尺如琉璃筒，放已右旋如頗梨珠，顯現無量百千色光，是名菩薩初生時白毫相光。

"How should one contemplate the mark of the Tathāgata's broad, flat, and upright forehead? Within the mark of the broad, flat, and upright forehead there are three marks. The first is what is called the mark of the white hair. When the Buddha was first born, the king and his lady took the Crown Prince to the rishi Asita to have him examine the Prince's marks. The rishi parted the fine cloth, and upon first seeing the white hair between the Prince's brows spiralling forth, with contours bordering the white hair that coiled along with it, the physiognomist stretched out the hair and saw that it was long and large. He immediately took a rule to measure its length, and it was a full five feet, like a tube of lapis lazuli. When released, it curled to the right like a crystal pearl, manifesting immeasurable hundreds of thousands of colored rays of light. This is called the light of the mark of the white curl at the time of the Bodhisattva's birth.