What is meant by the word "أم" (am) that was repeated several times in Surat At-Tur?

The preponderant view regarding the meaning of "am" repeated in Surat At-Tur from verse 30 to 43—mentioned fifteen times—is that it is understood as "bal" and the hamza (bal a), which is the opinion of the majority of grammarians. "Bal" indicates a transition from clarifying what precedes it to clarifying what follows it, and the hamza is for denial and disapproval of their statement. Thus, the meaning would be "Rather, do they say, 'A poet'?" or "Rather, do their dreams command them to this?"