When you're a 5, you're not thinking 10
You're not seeing 7, you're not even 6
The numbers refer to the 1 to 10 scale on which people rate others or themselves. Lil b is stating that his haters who live on a lower state such as 5 are unable to understand the wisdom of people thinking on a more elevated level.
This is the resason he has chosen to forgive his haters. He has realized that they are simply unable to understand him because they think on a lower level.
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