But in the fourth generation they shall come here again: for the iniquity of the Amorites is not yet complete.
All Commentaries on Genesis 15:16 Go To Genesis 15
Ambrose of Milan
AD 397
The history of the Jews, who went down into Egypt and came out from Egypt, seems to accord with this. The years they spent there were , but not all of them lived a hundred years and more, as did Moses and Joshua, so that the time of the fourth generation would be appropriate in this context. So let us search rather for a mystical sense. In fact, the number four adapts well to all numbers, and it is in a certain sense the root and base of the decimal. It also represents the midpoint of the number seven. In fact, the ninetythird psalm is entitled “fourth day of the week” because this number is the intermediary between the first three and those that follow. In fact, three days precede it: the first, the second and the third; and three follow: the fifth, the sixth, the seventh. One who sings this psalm is proceeding through the life of this world, so to speak, in accordance with aptly placed numbers, like a quadrangle stable and perfect. In four books the Gospel is complete and perfect. There are four mystical animals; and there are also four parts of the world, from which the assembled children of the church have propagated the most holy kingdom of Christ, coming from east and west and north and south. The holy church, therefore, has arisen with four sides. The decade too derives from this number. For if you total up the numbers from one to four you will have the number ten. Count one, add two to this: this makes three. Add three to three, this makes six. And to six add four, and this makes ten. Four then generates the decade, and the decade includes all numbers. Four is also the number of ages of a man: childhood, adolescence, virility and maturity. He rises gradually, and his wisdom is consolidated. Thus the fullness of wisdom comes, considering the ages, in fourth place. For this reason even if one has formerly been subjected to the king of Egypt, nevertheless with the age of maturity he is freed from his power and acknowledges his duty to follow the law. Then the sea of this life opens up to him. .
