ואברם כבד מאד במקנה, this is why he had to travel slowly, even though he wanted to return quickly to the site of the altar where he wanted to continue his preaching as he had done before the famine.

וילך למסעיו, this is why he traveled on his routes, i.e. the routes all the shepherds took when journeying in that direction.

ולא נשא אותם הארץ, the grazing land available in that region was inadequate for their combined herds.

ויהי ריב בין רועי מקנה אברם ובין רועי מקנה לוט, there was an argument between who would succeed to drive out the other from the available grazing land they would find.

והכנעני והפריזי אז יושב בארץ. This is why a quarrel between two brothers who lived side by side was especially embarrassing and harmful to the image of Avram among the surrounding tribes. When those tribes would see the brothers quarrel, they would assume that neither of them was a peace-loving individual and they would reason that they had even more reason to quarrel with either one of those recent immigrants.

ביני ובינך, in the future. When either one of them would select for his herds a certain grazing area.

אל נא תהי מריבה, the result of competing aspirations to the same grazing land.

ובין רועי ובין רועיך, now that we dwell here.

הלא כל הארץ לפניך, I’ll let you choose the area which you prefer.

Therefore, הפרד נא מעלי, move away from me in the direction you prefer and I will move in the opposite direction. If you select grazing land to the left, I will select grazing land to the right.

ויבחר לו לוט, he selected as much area as he himself with his shepherds would manage to control as their grazing land. In this section of the earth Avram and his shepherds would not be allowed to graze.

ויסע לוט מקדם, he did not turn right or left which were north and south, but he moved from the east to the west to distance himself from Avram [the author translated מקדם as meaning “from the east,” though this is difficult to reconcile with the fact that the Jordan valley is east from the region of Bet El and Ai where Avram and Lot had been reported last in verse 3. The area of the Jordan valley was the area from which the Israelites under the leadership of Joshua would enter the land of Canaan (Joshua chapter 4)

אברם ישב בארץ כנען, even though the city of Sodom and its satellite towns are on the border of the land of Canaan, the people living in those cities at that time, were not Canaanites. It was therefore in order for the Torah to write that Avram- as opposed to Lot- settled in the land of Canaan. He settled in the part of the land inhabited by Canaanites. They were not as evil as the Sodomites. Avram did not move close to the boundary of Sodom at all.

אחרי הפרד לוט, G’d did not say what follows while Lot was still in Avram’s company, so that the latter would not boast and his shepherds would engage in stealing grazing land from the local inhabitants claiming G’d’s promise to Avram of future possession as their justification.

לך אתננה, for even in your own lifetime you will be regarded as a prince of G’d, and deserving of great honour (compare Genesis 23,6)

ויאהל אברם, an expression denoting the encamping, erecting one’s many tents.