Charles Ellicott Commentary Matthew 3:9

"and think not to say within yourselves, We have Abraham to our father: for I say unto you, that God is able of these stones to raise up children unto Abraham." — Matthew 3:9 (ASV)

We have Abraham as our father — The boast seems to have been common, as in John 8:33-39, and was connected with the belief that this alone, or taken together with the confession of the creed of Israel, the Lord our God is one Lord (Deuteronomy 6:4), would be enough to ensure admission into Paradise for every Jew. The 'bosom' of Abraham was wide enough to receive all his children. We have Abraham as our father was to the Jew all and more than all that "civis Romanus sum" was to the Romans.

Of these stones — The words were obviously dramatized by gesture, pointing to the pebbles on the banks of the Jordan. In their spiritual application, they are remarkable as containing the germs of all the teaching of our Lord, and of St. Paul, and of St. John, as to the calling of the Gentiles and the universality of God’s kingdom.