Sefer HaBahir 7

1Rabbi Amorai sat and expounded, "Why is it written 'And full of the blessing of YHVH, he will take possession of the west and south' (Deuteronomy 33:23)? Thus Moses said, 'If you walk in His laws, you will inherit this world and the next world.' The world to come is compared to the sea, as it is said 'And [it is] wider than the sea' (Job 11:9). And this world is compared to the south, as it is said '[Give me a blessing,] for you have placed me in the land of the Negev [the southern desert]' (Joshua 15:19), and from our targum [this is translated into Aramaic as], 'Behold, the earth is the south' (Targum Jonathan, Joshua 15:19)."