Mark 12:26

And as touching the dead, that they rise
For the proof of the doctrine of the resurrection of the dead,

have ye not read in the book of Moses;
that is, in the law of Moses; for though it was divided into five parts, it was but one book; just as the Psalms are called the Book of Psalms, ( Acts 1:20 ) , and the Prophets, the Book of the Prophets, ( Acts 7:42 ) . The book of Exodus is particularly intended; for the passage referred to is in ( Exodus 3:6 ) ,

how in the bush God spake unto him,
or "out of the bush", as the Syriac and Persic versions read;

saying, I am the God of Abraham, and the God of Isaac, and the God
of Jacob? (See Gill on Matthew 22:31), (See Gill on Matthew 22:32).