Son of David.

After Matthew had said "Jesus," he added "Son of David," so that you might not think that he was speaking of another Jesus, for there was another famous Jesus, the leader of the Jews after Moses. But this one was called the son of Nun, and not the son of David. He had lived many generations before David, and was not of the tribe of Judah from which David came, but of another.

Son of Abraham.

Why did Matthew put David before Abraham? Because David was more famous; he lived later than Abraham, and was a glorious king. Of the kings, he was the first to please God and received a promise from God that Christ would arise from his seed, which is why everyone called Christ the Son of David. And David actually retained the image of Christ in himself: just as he reigned in the place of the rejected and hated Saul, so Christ came in the flesh and reigned over us after Adam lost the kingdom and power that he had over all living things and over the demons.

Abraham begat Isaac.

The evangelist begins his genealogy with Abraham because he was the father of the Jews, and because he was the first to receive the promise that "in his seed all nations will be blessed." And so, it is fitting to begin from him the genealogy of Christ, for Christ is the seed of Abraham, in whom all of us who were pagans and were formerly under a curse received a blessing. Abraham means "father of tongues", and Isaac means "joy", "laughter". The Evangelist does not mention the illegitimate children of Abraham, for example, Ishmael and others, because the Jews did not descend from them, but from Isaac.

Isaac begat Jacob; And Jacob begat Judah and his brethren.