“And whatever name the man called each living creature, that was its name” (Bereishit 2:19)
From this pasuk, we learn that a person’s name is the essence of his neshamah (Oheiv Yisrael, Shemot, Parashat Zachor).
“And the man gave names to all the cattle and to the birds of the sky and to every beast of the field; but as for man, he did not find a helpmate that matched him” (Bereishit 2:20)
The Radak states that Adam called the creatures names in lashon hakodesh. This was the language of mankind until the Generation of the Dispersal. The Ramban says that Adam gave names to the creatures so that they could be discerned by these names forever. He knew their characteristics and named them appropriately, each according to its nature.
“Your name shall no longer be called Avram, but your name shall be Avraham, because I have made you the father of a multitude of nations” (Bereishit 17:5)
The Chizkuni says that it is customary to change one’s name when he rises in stature. We find this regarding Sara, Yaakov, Yitzchak, Yehoshua, Chananiah, Mishael, and Azariah.
A person should be careful in choosing a name for his child, for a name can cause good or harm (Tanchuma, Ha’azinu 7).
“ אשר שם שמות בארץ– Who has wrought desolation in the land.” The wordשַמוֹת (desolation) can be read as שֵמוֹת, meaning names. From here we learn that the name of a person or place causes certain actions. We name our children after previous generations (Sechel Tov, Bereishit 46).
How do we see that a name causes specific actions? Rabbi Eliezer cites the following passage (Tehillim 46:9): “Go and see the deeds of Hashem, Who has wrought desolation in the land.” The word שַמוֹת(desolation) can be read as שֵמוֹת, meaning names. From here we learn that the name of a person or place causes certain actions (Berachot 7b).
Rabbi Yitzchak says that there are four things which can rescind a harsh decree. One is a change of name, as the pasuk states (Bereishit 17:16), “As for Sarai your wife – do not call her name Sarai, for Sarah is her name.” In the next pasuk, we read, “I will bless her; and I will also give you a son through her” (Rosh Hashanah 16b).
The Ritva expounds: Changing a person’s name converts him into a new being, free of sin. His previous sins are a thing of the past and have no bearing on him any longer.
Even if a person is mired in sin, to the extent that he deserves severe punishment, he should never despair of Hashem’s mercy and the power of prayer and teshuvah. He should increase his prayers and tzedakah and change his actions. He should use strategies to arouse himself by means of changing his behavior, such as changing his name. This will cause him to act differently, like a new person. Changing one’s place also has this effect (Beit Habechirah LaMeiri).
When a baby boy is circumcised, his father names him. He is not named randomly, but Hashem places the name in the mouth of his father, and it is immediately noted on the Heavenly Throne if he will be righteous (Emek Hamelech, in the name of the Ari).
