He also said the USA only wants to topple Iran's ally Assad to help out Israel.
Right. He’s warning the mujahideen in Syria against doing what the Muslim Brotherhood did in Egypt: compromising with secular interests, which resulted in them not implementing sharia and maintaining relations with Israel - the 2 no-no’s for jihadist regimes. Seems to me that he is saying that the Muslim Brotherhood is mujahideen but made the mistake of compromising with secularists.