Yet before us, i.e. in our power, as that phrase is oft used. See Poole on "Genesis 13:9".
Related Commentaries of 2 Chronicles 14:7
2 Chronicles 14:7
7 Therefore he said unto Judah, Let us build these cities, and make about them walls, and towers, gates, and bars, while the land is yet before us; because we have sought the LORD our God, we have sought him, and he hath given us rest on every side. So they built and prospered.