This mountain, i.e. this mountainous country, in which was Hebron, Joshua 11:21, Joshua 20:7, and Debir, and Anab. He names the country rather than the cities, either,
1. Because the giants here following were already driven out of their cities, but yet abode in their caves or holds in the mountains, whence they much molested the Israelites. Or,
2. Because the cities were given to the Levites, Joshua 21:11,13. Thou heardest, i.e. didst understand, both by the reports of others, and by thy own observation, as I also did. Hearing, the sense by which we get knowledge, is off put for knowing or understanding, as Genesis 11:7, Genesis 42:23 2 Kings 18:26. If so be the Lord will be with me; a modest, and humble, and pious expression, signifying both the absolute necessity of God's help, and his godly fear, lest God for his sins should deny his assistance to him, as he might justly do; for although he was well assured in general that God would crown his people with success in this war, yet he might doubt of his particular success in this or that enterprise. To drive them out; out of their fastnesses, where they yet remain. Caleb desires this difficult work as a testimony of his own faith, and as a motive to quicken and encourage his brethren to thee like attempts.