How did the Wise Men know? The Wise Men/Magi were educated and notable men who studied the stars and apparently knew the prophecies well. It is thought to have been Daniel who first introduced the Magi to the Holy Scriptures of the God of Israel. It is believed that throughout the centuries these men had studied the Hebrew Scriptures and therefore understood the timing of the Messiah's birth and the sign that would lead them to the place where He would be born. But how did they know? The Bible doesn't explicitly tell us, but we can find reasoning in the Scriptures that provide some answers.
The Timing of the Messiah's Birth
In Daniel 9:24-26 is given a clear prophecy of the Messiah who would present Himself to His people, would be hailed as the One who would come in the name of the Lord and then be killed. This passage gives a timeline from the decree to rebuild Jerusalem, to the Messiah's entry into the city and then to His being "cut off" (killed).
Seventy weeks are determined upon thy people [the Jews] and upon thy holy city [Jerusalem]... (Daniel 9:24a).
Seventy weeks means seventy years. Just as we would say three dozen equals 36, or seven decades equals 70 years, the Jews understood the word "weeks" to mean seven. So in Daniel 9:24 "seventy weeks" means seventy sevens or 70 x 7 = 490 years.