The Israelites did not call Ishmaelites there brethren. So, the Prophet was referring to a Israelite. Muhammad wasn't a Israelite, throughout the Old Testament one often finds the expression "their brethren" meaning the remaining tribes of Israel. What is a Prophet like Moses? Deuteronomy 34.11 makes it essential that the prophet like Moses would do similar signs and wonders to those which Moses did, and as Muhammad did not. Muhammad couldn't do a Miracle: According to Surah 28.48, Muhammad could not give a miracle.