What is the reason for the indefinite and definite articles in verses 126 of Surat Al-Baqarah and 35 of Surat Ibrahim?

Perhaps the indefiniteness of "baladan" (a town/city) in Ibrahim's supplication in Surat Al-Baqarah is because he asked Allah to make the empty valley a flourishing town where people would feel secure, and that was when he settled his family in Mecca, where there was no one and no water. As for its definiteness in Surat Ibrahim, it is because the supplication was made after Mecca had become a stable and populated town. The exegetes have unanimously agreed that the city prayed for in both surahs is Mecca Al-Mukarramah.