Parshas Lech Lecha
"Vayikra Beshem Hashem" and Abram called out in the name of Hashem.
Ramban----Abram called out in a strong voice [why wasn’t this said before in Charan, Urkasdim] since here it was said in a strong voice, people listened to him.
Rabainu Bachayee---Abram publicized the chessed that Hashem does with people. [Here is the first time he used a public forum, by doing it in front of the alter. – Radak]