Good Hobbit Morning chapter 11 "On the doorstep"

"Bilbo sat gloomily staring at the stone ground, hoping for Gandalf to return. As the sun turned west, the light caught the tops of a distant forest, and he espied a thin new moon in the sky. Then he heard a crack behind him, and saw a large, black thrush knocking a snail against the stone of the wall. Recalling the words of Thrór's Map, he suddenly understood, and, setting aside all danger he called urgently for the Dwarves and explained the knocking of the thrush to them. But the sun sank lower and their hopes fell, until it sank into cloud and disappeared. As they had almost given up, a red ray of sunlight gleamed onto the smooth rock wall: the last light of Durin's Day. The thrush gave a trill, and with a loud crack, flakes of rock fell, opening a hole in the lower part of the stone wall."