20 While he was trying to figure a way out, he had a dream. God's angel spoke in the dream: "Joseph, son of David, don't hesitate to get married. Mary's pregnancy is Spirit-conceived. God's Holy Spirit has made her pregnant. 21 She will bring a son to birth, and when she does, you, Joseph, will name him Jesus - 'God saves' - because he will save his people from their sins." 22 This would bring the prophet's embryonic sermon to full term: 23 Watch for this - a virgin will get pregnant and bear a son; They will name him Emmanuel (Hebrew for "God is with us"). 24 Then Joseph woke up. He did exactly what God's angel commanded in the dream: He married Mary.
Matthew Henry's Commentary on Matthew 1:20-24
Commentary on Matthew 1:18-25
(Read Matthew 1:18-25)
Let us look to the circumstances under which the Son of God entered into this lower world, till we learn to despise the vain honours of this world, when compared with piety and holiness. The mystery of Christ's becoming man is to be adored, not curiously inquired into. It was so ordered that Christ should partake of our nature, yet that he should be pure from the defilement of original sin, which has been communicated to all the race of Adam. Observe, it is the thoughtful, not the unthinking, whom God will guide. God's time to come with instruction to his people, is when they are at a loss. Divine comforts most delight the soul when under the pressure of perplexed thoughts. Joseph is told that Mary should bring forth the Saviour of the world. He was to call his name Jesus, a Saviour. Jesus is the same name with Joshua. And the reason of that name is clear, for those whom Christ saves, he saves from their sins; from the guilt of sin by the merit of his death, and from the power of sin by the Spirit of his grace. In saving them from sin, he saves them from wrath and the curse, and all misery, here and hereafter. Christ came to save his people, not in their sins, but from their sins; and so to redeem them from among men, to himself, who is separate from sinners. Joseph did as the angel of the Lord had bidden him, speedily, without delay, and cheerfully, without dispute. By applying the general rules of the written word, we should in all the steps of our lives, particularly the great turns of them, take direction from God, and we shall find this safe and comfortable.