Stones of Substance
When Rabbi Chanina HaGadol went from Babylon to Eretz Yisrael there were no signposts or border guards to indicate that he had reached his destination. But he had his own litmus test. He would pick up stones and feel their weight. As long as the stones were light he would cast them aside with a sense of disappointment that he had yet not reached his goal. When he finally picked up some stones of real substance he declared that these were “Eretz Yisrael stones,” and he kissed them in fulfillment of King David’s words “Your servants hold dear her stones” (Tehillim 102:15).
(Midrash Tanchuma, Parashat Shelach, quoted by Tosefot in Ketubot 112a)