Subhana Rabbiyal Azim means glorifying the One Who possesses ultimate greatness. Subhana Rabbiyal A’la means glorifying the One Who is exalted in His Essence.

There is nothing wrong with the Muslim reciting the du’a for entering the marketplace, seeking reward with Allah. If the hadith mentioning the reward is proven sound, then praise be to Allah; if it is not, then he will still attain the reward for remembering Allah in general, which is one of the most beloved of deeds to Allah.