Who was the leader who brought God's people into the land God had promised them?

The leader who brought the people into the land the first time was JOSHUA. Ezra, Nehemiah, and Zerrubabel brought them in the second time, and the modern Zionists brought them back the third time.

You will find the covenant made with Abraham, Isaac and Jacob in Genesis 16 & 17

You can read about Moses and Joshua in the books of Exodus, Deuteronomy and Joshua