1. that he will not be defeated until Burnum Wood moves to Dunsinane Hill (he believes the woods will not move so he won't be defeated)
2. the witches tell him that no one born of a woman will harm him (natural birth) so he will not be defeated. Though Macbeth doesn't pay close attention to the first prediction (to be weary of Macduff; foreshadowing when - spoiler - Macduff kills him because he was born through a C-section)
hope this helped!
