The Torah identifies the events that are about to unfold as occurring in the days of Amrafel. Who was Amrafel, and why was he called by that name?
Rashi and Targum Yonasan: He was alias Nimrod, and the name Amrafel is the acronym of "Amar Pol," because he ordered Avraham to fall into the fiery furnace. 1
Seforno: He was a well-known leader of his generation, and it was in his time that Aryoch, Kedorla'omer and Tid'al initially fought the five kings (though Amrafel himself was not involved in the war at this point). 2
Over which nations ("Goyim") was Tid'al king?
Rashi: "Goyim" is the name of a country, so-called because people from all over gathered there. 1
Targum Onkelus and Targum Yonasan: He was a king to whom many nations paid allegiance. 2
What is the underlying hint in the Parshah ('Ma'aseh Avos Siman la'Banim')?
Ramban (citing the Midrash): The Parshah hints at the four kingdoms that will come to power in the course of history, who will initially subjugate Avraham's descendants, but over whom B'nei Yisrael will eventually overcome and recover their property. Shin'ar is Bavel; El'asar represents Madai; Eilam
What is the connotation of "va'Yehi bi'Yemei"?
Ba'al ha'Turim, citing Bereishis Rabah: This appears in five places; in all of them, it means Vai (woe, misery). 1 See also Megilah 10b.
Divrei Eliyahu, Hashmatos ha'Gra (Yeshayahu 11:10): One opinion in the Midrash says that va'Yehi always means "woe." This can be explained as follows, the letter Vav switches what should have been in the future (e.g. Yehi Ohr (Bereishis 1:3)) to a matter of the past (that light was hidden away, due to people not worthy of it). Conversely, v'Hayah always means Simchah. It switches what initially was not, and now it is.
QUESTIONS ON RASHI
Rashi writes: "Amrafel was Nimrod." What is the source for this interpretation?
Gur Aryeh: The verse aims to clarify for us when these events took place, "And it was in the days of Amrafel..."
Rashi writes: "...Those nations appointed a king over them, whose name was Tid'al." But perhaps the nations first appointed another king, naming the place Goyim; and Tid'al only ascended their throne at a later date?
Migdal Bavel and the Dispersion of mankind into various nations had only occurred only about 27 years prior to the war described in this Perek. 1 Rashi asserts that just as Amrafel (also known as Nimrod) was of the first generation of kings in history, 2 so was Tid'al. 3 (CS)
The Dispersion took place in the year of Peleg's death (Rashi to 10:25). Avraham was then 48 (Rashi to 19:20), and upon his arrival in Eretz Kena'an he was 75.
See also Seforno to 14:3