expression, yodan verb with 'ru' ending (archaic)
don't eat plum pits (because they are poisonous); if you eat a plum, don't eat the kernel; inside it heavenly gods sleep
Proverb warning against eating plum pits, which contain toxic compounds. The literal image is that a deity (Tenjin) sleeps inside the pit, so eating it would be disrespectful and dangerous.
祖母はよく「梅は食うとも核食うな、中に天神寝てござる」と言って、梅干しの種を取ってくれた。
My grandmother often said, 'Don't eat the plum pit; inside it, the heavenly god sleeps,' and would remove the pit from the pickled plum for me.
A traditional Japanese proverb. The exact origin is uncertain, but it reflects folk beliefs about the toxicity of plum pits and the reverence for Tenjin (Sugawara no Michizane), a deified scholar associated with plums.