Proof of funds letter

[Nick Stango]

My brother is lending me money to purchase my first fix and flip for a pretty hefty interest rate, but my realtor needs a proof of funds letter, he wants me to find a property first and present the deal to him for his approval before he will give any form of proof of funds letter for that property. My realtor wants the letter so she knows I'm a serious cash buyer. How does this usually work? I've heard a few different things. Does anyone have some insight on this topic?