“Before I lose, I search.” That is, the old man who walks always looks at the ground, as though searching for something (Shabbat 152).
We should understand what this comes to tell us. An old man is one who has acquired wisdom. Before he loses the fear of heaven, he searches in the earth, for earth is an intimation of the fear of heaven. He does not wait until he loses his fear of heaven, and then he searches, but rather “The wise sees the future” and searches in advance.