יב:א וַיֹּאמֶר ה’ אֶל אַבְרָם לֶךְ לְךָ מֵאַרְצְךָ
לֶךְ לְךָ … רמז לו שלאחר שתלך מארצך תחיה כמנין לך לך , שהרי בן ע”ה  שנה היה כשיצא וכל שנותיו קע”ה .
This week’s Parsha opens up with HaShem’s command to Avram: Lech-Lecha – “Go for yourself,” for your own good, and I will shower you with blessings. How long did these wonderful blessings last?
The Baal HaTurim, written by Rabbi Yaakov ben Asher around 800 years ago, says that they lasted for at least 100 years, the same as the numerical value of Hashem’s command: Lech Lecha – לֶךְ לְךָ.
Why 100? Because that is how long Avram lived after receiving these blessings. He was 75 years old at the time and he passed away at the age of 175.
175 – 75 = 100.
So, the blessings which came with the commandment of lech lecha lasted “lech lecha” years: 100 years!