Garudapurana 1.19.2

1.19.2

citāvalmīkaśailādau kape ca vivare taroḥ /
daṃśe rekhātrayaṃ yasya pracchannaṃ sa na jīvati //

Upon a funeral pyre, an anthill, a mountain, and the like, in a well, in the hollow of a tree: / he whose bite shows three concealed lines does not survive;