釋氏要覽 1.246

1.246

律云。毀其形好。剃除鬚髮。俾即發先業。使異餘出家者○因果經云。過去諸佛。為成就無上菩提故。捨飾好。剃鬚髮。即發願言。今落髮故。願與一切眾生斷除煩惱。及以習障（此悉達太子。剃髮之時言也）。

The Vinaya states: 'One mars one's fine appearance and shaves off beard and hair, causing one to immediately renounce prior karma and setting one apart from other renunciants.' / The Guoqu xianzai yinguo jing states: 'Past buddhas, in order to achieve unsurpassable bodhi, abandoned adornments and shaved their beards and hair, making the vow: "Now as my hair falls, I vow to sever afflictions and habitual obstructions together with all sentient beings!"' (These were the words of Prince Siddhārtha when his head was shaved).