金光明最勝王經疏 6.169

6.169

下次見虎飢羸。問：見虎生子，寧知七日：答真諦三藏二解。一云：段食所資唯至七日，過此便死。虎飢如是，故知七日。一云：于時應有鬼神噵之，但經家不出。亦如捨身發願，無人聞知，後天神報，如樹神噵池中魚數。

Below, next: seeing the tigress hungry and emaciated. Question: Seeing the tigress give birth to cubs, how did they know it was seven days? Answer: Tripiṭaka Master Paramārtha gave two explanations. One says: Food taken in morsels can only sustain life up to seven days; beyond this, one dies. The tigress was hungry like this, hence they knew it was seven days. The other says: At that time there must have been ghosts or spirits who told them, but the compiler of the sūtra did not mention it. It is also like when the body was relinquished and the vow was made, no human heard or knew, but later a deva reported it; just as the tree deity told the number of fish in the pond.