Sunan at-Tirmithiy كتاب الصيد والذبائح باب ما جاء فيمن يرمى الصيد فيجده ميتا فى الماء
When the Messenger of God, peace and blessings of God be upon him, was asked about game he replied, "When you shoot your arrow, invoke the name of God. If you find that it has killed (the game), then eat; unless you find that it (the game) has fallen into water, then do not eat, since you do not know whether it was the water that killed it or your arrow (1)." Footnotes: (1) If, however, it is proven to the hunter that the animal fell into the water after its death by his arrow, then it is permissible to eat its meat. Click on ḥadīth to read more