102 But what is the meaning of his having arranged his wives and children and all his servants, and ordered that they should bow down to the earth? It was certainly not to the element of earth, which is often filled with blood, in which is the workshop of all crimes, which often is rough with huge rocks, or broken cliffs, or barren and hungry soil, but as to that Flesh which is to be for our salvation. And perchance this is that mystery which the Lord taught, when He said: “Not only seven times, but even seventy times seven.”
Source: Letters (New Advent)