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.

'To smite' signifies condemnation.

'To smite the earth with every plague as often as they will,' as in Revelation 11:6, signifies the destruction of the church by all kinds of evils and falsities.

Among the ancients, who lived in an age of representatives and meaningful signs, 'to smite the mother with the children' was a proverbial expression meaning the destruction of the Church and of everything that belonged to the Church either in general, or in particular with anyone who in himself is a Church. 'Mother' was used to mean the Church, and 'children' or 'sons,' truths which belonged to the Church. So 'to smite the mother with the children' means to perish completely, as a person also perishes completely when the Church and what belongs to the Church perishes in him, or when the affection for truth, which is the meaning of 'mother' and constitutes the Church in a person, is destroyed. 

'To smite,' as in Genesis 32:8, signifies destruction.

In Genesis 14:15, this signifies vindication.

(Verweise: Arcana Coelestia 7871)