Malbim: First, Hashem said "all the men? will not see the land? My servant Kalev? I will bring him to the land that he came, and his seed will inherit it", "If you will come to the land? except for Kalev and Yehoshua" (14:22-24,30). Since the latter verse promises that they will come to the land, the former verses must mean that his seed will inherit the place that Kalev himself came to, i.e. Chevron.