Tafsiran Kejadian 12:4: Chizkuni, Da'at Zekenim, Or HaChaim & Radak

וילך אתו לוט, “Lot (his nephew) went with him.” Seeing that the death of Lot’s father Haran was indirectly due to Avraham who had been saved from Nimrod’s furnace a deed Haran emulated, but only after having seen Avraham being saved Avraham did not feel he could reject him at this stage. He adopted him as if he had been his own son.

ואברם בן חמש שנים ושבעים שנה בצאתו מחרן “and Avram was seventy five years old when he left Charan.” At first glance this statement is puzzling as the covenant of the pieces is reported as if it had occurred later than Avram’s departure from Charan (chapter 15). According to our tradition it took place 30 years before the birth of Yitzchok, and this is what the statement that the Israelites spent 430 years in Egypt, reported in Exodus 12,40 is based on. We know as a fact from the Torah that Avraham was one hundred years old when Yitzchok was born. According to Rashi, thirty years elapsed between the covenant of the pieces and the birth of Yitzchok. If so, Avraham could not have been more than 70 years old at that event. Lot joined him and was taken captive after having separated from Avraham during that same year still, and Avraham defeated the armies which had taken him captive, after which event G–d appeared to him as reported in chapter 15. He returned to Charan once more, and when he was 75 years old, G–d commanded him to move to the land of Canaan, i.e. “the land which I will show you.” (12,1) I have found confirmation of these dates in the book called Seder Olam, an ancient historical record, considered reliable by our sages. I am quoting verbatim from that text: “Avraham was 48 years old when G–d confused the languages of the people and they moved apart from one another. When G–d spoke to him at the covenant of the pieces, he was 70 years old. (this was while he was on the soil of the land of Canaan). He returned to Charan where he stayed for another five years. It follows that 27 years elapsed between the destruction of the Tower and Avraham’s departure from Charan a second time” Our verse refers to the second departure.

וילך אברם, Abram went, etc. In view of verse 5 which describes Abraham's journey in detail, this entire verse seems superfluous.