Abraham made a covenant with the people of the land, and when the angels presented themselves to him, he thought they were mere wayfarers, and he ran to meet them, purposing to make a banquet for them. This banquet he told Sarah to get prepared, just as she was kneading cakes. For this reason he did not offer them the cakes which she had made, but " ran to fetch a calf, tender and good." The calf in trepidation ran away from him and hid itself in the cave of Machpelah, into which he followed it. Here he found Adam and Eve fast asleep, with lamps burning over their couches, and the place pervaded with a sweet-smelling odor. Hence the fancy he took to the cave of Machpelah for a " possession of a burying-place. "
The Calf That Led Abraham Into the Cave of Machpelah
Pirkei DeRabbi Eliezer 36