But the supreme form of bedurya is more extraordinary. Mahayana teachings such as the Lotus Sutra indicate it is in fact an extremely precious relic, an utterly pure blue light radiating from the bodies of fully enlightened buddhas that brings health and happiness to all beings. This is also why the Medicine Buddha is called the King of Bedurya Light. His rays are said to pervade all directions of samsara, blessing all beings and curing their physical and mental ailments, and negative karma.
“And when I have arrived at awakening, may my body be like a precious beryl, perfectly flawless inside and out, bright, brilliant, large, great, firm, well fixed, fully ornamented with a net of rays surpassing the moon and sun!”
Medicine Buddha Sutra
(translated by Gregory Schopen, Buddhism and Medicine, 2017, p. 238)