See this passage fully explained in the notes at Matthew 22:23-33.
Are as the angels - That is, as the angels in respect to connections and relations. What those connections and relations may be we know not, but this passage teaches that the special relation of “marriage” will not exist. It does not affirm, however, that there will be no recollection of former marriages, or no recognition of each other as having existed in this tender relation.
How in the bush - At the burning bush. See Exodus 3:16. The meaning is, “in that part of the book of Exodus which contains the account of the burning bush. When there were no chapters and verses, it was the easiest way of quoting a book of the Old Testament “by the subject,” and in this way it was often done by the Jews.