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.

3565. 'And he blessed him' means resulting conjunction. This is clear from the meaning of 'being blessed' as conjunction, dealt with in 3504, 3514, 3530. In this state however the conjunction was none other than that described in 3563. Inmost, but not intermediate, conjunction existed with truth represented by Jacob, so that it was a conjunction through the end in view, which is inmost good and which could be actualized in this way and no other way. When such an end exists a conjunction of inmost things with outermost ones is effected first. Intermediate conjunction comes gradually. This the end brings about, for all progress lies with the end. Indeed the Lord acts through ends, and by means of them gradually re-arranges intermediate things into proper order. This is the origin of the conjunction meant by the reference to Isaac blessing Jacob.