'Offspring' in the Bible

The angel answered and said to her, “The Holy Spirit will come upon you, and the power of the Most High will overshadow you; and for that reason the holy Child shall be called the Son of God.

As He spoke to our fathers,To Abraham and his descendants forever.”

and they questioned Him, saying, “Teacher, Moses wrote for us that if a man’s brother dies, having a wife, and he is childless, his brother should marry the wife and raise up children to his brother.