It is written in last week's parsha, Parshas Noach that Terach begot Avraham at the age of seventy and it is written in the last possuk of last week's parsha that Terach died when he was two hundred and five years old.
The Medrash asks that four pessukim later, in our parsha, Parshas Lech Lecha it is written that Avraham left Charan to come to Eretz Yisroel when he was seventy five years old. Making a simple calculation it comes out that at that time Terach was one hundred and fourty five years old (Terach begot Avraham when he was seventy plus the seventy five years of Avraham equals one hundred and fourty five), and therefore he still had sixty years to live after Avraham came to Eretz Yisroel! Why then is it written in last week's parsha that he died?
The Medrash explains firstly that wicked people are called dead even when they are still living. In addition to this, the Medrash explains that Avram was hesitant to leave his father and go to Eretz Yisroel because by doing so he will cause Hashem's name to be disgraced. People will mock Hashem for commanding Avraham to leave his elderly father. Hashem therefore calmed Avram and told him, "I will exempt you from honoring your father and mother. However, I will not exempt others from honoring their parents and further more I will write that he died before it is written that you left your house and him".
Zera Shimshon asks what did Hashem gain by writing Terach's passing away before it is written that Avraham left him, when everyone who lived there at that time saw that Avraham left his elderly father.
He answers that in truth Avraham's leaving his father would not have disgraced Hashem's Name. People would understand that since Avram chose a different life style than his father, in that Avram lived according to Hashem's commandments while his father at that time still worshipped avodah zara they couldn't live together. The reason that Avram was concerned, though, was because people would criticize him and Hashem for leaving because at that time Terach began the teshuva process. They would say that since Avram felt that everyone should follow Hashem's mitzvos and his father began to go down that path, it would be proper for Avram to stay back and help his father to continue down the path that Avram followed.
Hashem replied to Avram that Avram's concern is valid for other people but not for him. Other people in Avram's situation should stay with their parents to assist them with the teshuva process. However, Avram's situation was different because at the Bris Bain HaBessarim, it is written v'atah tahvoe ell avosechah b'shalom" you will come to your ancestors in peace, which means that Hashem promised Avram that his father would do teshuva and after Avram passes away he will be together with him. Therefore even if Avram would leave his father behind, his father would become a baal teshuva and go in Avram's way so there is no reason to stay back with him.
The question is though, that the Bris Bain Habessarim, is written at the end of the parsha after Avram left his father. How then will people justify Avram's leaving with a fact that didn't yet happen?
The answer is that that according to Tosafos (Berachos 7b) even though that the incident of Bris Bain Habessarim was written after Avram came to Eretz Yisroel, it really happened five years earlier before Avram came to Eretz Yisroel. It was written afterwards because, ain mukdam u'me'oocher b'Torah- the Torah is not always written in the correct chronological order.
Zera Shimshon concludes that according to this we can now understand why Hashem wrote that Terach passed away before Avram came to Eretz Yisroel even though that he passed away sixty years later.
People at that time knew of the promise to Avram that his father will eventually do teshuva even without Avram's help. However, people later on who learn Chumah will wonder how could it be that Hashem told Avram to leave his father who began to repent on all his misdeeds and began the teshuva process. Hashem therefore wrote Terach's passing away obviously out of order so people will realize that ain mukdam u'me'oocher b'Torah- the Torah is not always written in the correct chronological order. They will therefore understand that the Bris Bain Habessarim was also written out of order and the promise that Terach will do teshuva happened before Avram left him. They therefore will not question how Hashem told Avram to leave his father who began the teshuva process.
Zera Shimshon gives another explanation why Terach's passing away is written before Avram came to Eretz Yisroel even though he died sixty years later.
Rashi writes in the name of the Medrash that the place "Ur Kasdim" has that name because Nimrod through Avram into a burning furnace after he broke the idols of his father. (Ur means a fire).
Another fact. It is written in Zohar Hakodesh that falling from one's status is considered to be a type of death.
Before Avram broke Terach's idols, Terach made a good living and had a high place in his society by selling his idols. However, after that incident people lost their trust in Terach's idols and he therefore fell both financially and socially.
To allude that he fell from his status, right after the Torah mentions that Avram, Terach, Lot and Sarah left Ur Kasdim the Torah writes that he died even though that he died much later!
