Sforno on Genesis 10:11/ספורנו על בראשית י׳:י״א

1מן הארץ ההיא יצא אשור, he emigrated from there because he disagreed with Nimrod politically, i.e. he opposed the building of the Tower (fearing that G’d would punish the people including his children who were associating themselves with rebellious project)

2ויבן את נינוה, because he had distanced himself from the plans undertaken by the four countries under the rule of Nimrod in the land of Shinor, G’d rewarded him to let him build the four cities mentioned here. This is an instance of אל פניו ישלם לו, of G’d recompensing someone for a good deed “to his face,” i.e. so that he can realise that this is what G’d has done for him. (Deuteronomy 7,10)