Such practice is quite common within east asia. It is called &#x27;sokushinbutsu&#x27; in Japanese, kanji of which translated into 即身仏, which means 肉身佛 in Chinese, literally &#x27;flesh body buddha&#x27;. From wikipedia, monk Hui Neng, dating back to 638 A.D. tang dynasty, seems to be believed the first of such example.<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Huineng" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Huineng</a><p>I cannot say I understand how this is explained from Buddhism within, because I am not practitioner. But if such thing happens, it is usually viewed as some kind of wonder&#x2F;miracle by the locals, and also means the monk has ascended to be Buddha.