Hundred
It's a landmark for a young child to count to 100; it sort of covers all the "ordinary" numbers. One hundred is obviously significant for other groupings: 100 cents is a dollar; 100 yards is a touchdown; 100 years is a century, and the landmark for a very long life. It makes sense, then, that in the Bible, 100 represents fullness or a state of completion, or in some instances simply "much." For instance, people marvel that Abraham had Isaac when he was 100 years old; the number represents the point at which the Lord, when growing up as Jesus, united the human elements of himself with the divine elements and in a sense became "complete.
Luke 1:67-75
67
His father, Zacharias, was filled with the Holy Spirit, and prophesied, saying,
68
"Blessed be the Lord, the God of Israel, for he has visited and worked redemption for his people;
69
and has raised up a horn of salvation for us in the house of his servant David
70
(as he spoke by the mouth of his holy prophets who have been from of old),
71
salvation from our enemies, and from the hand of all who hate us;
72
to show mercy towards our fathers, to remember his holy covenant,
73
the oath which he spoke to Abraham, our father,
74
to grant to us that we, being delivered out of the hand of our enemies, should serve him without fear,
75
In holiness and righteousness before him all the days of our life.
