Why did Allah not mention the complete number in His Almighty saying: "And We sent him to a hundred thousand or even more" and what is the meaning of "or even more"?

The verse intends to show the large number of people to whom Yunus (peace be upon him) was sent, or that their number varies depending on the consideration of the count or the counter. The point is that the increase is not excessively large. The increase could be due to the second mission, or that they were the Jews and those who joined them from the inhabitants of Nineveh. The word "or" (أو) in the verse has three interpretations:

1. It means "rather" (بل).

2. It means "and" (الواو).

3. It retains its original meaning, i.e., "or they exceed in your estimation." This is a form of address using what people understand, or to keep the number vague for the addressee while the speaker knows it.