And let it come to pass, that the damsel to whom I shall say, Let down your pitcher, I pray you, that I may drink; and she shall say, Drink, and I will give your camels drink also: let the same be she that you have appointed for your servant Isaac; and thereby shall I know that you have showed kindness unto my master.
Read Chapter 24
Caesarius of Arles
Now, dearly beloved, let us briefly see, as far as we can, what these facts mean. When blessed Abraham directed his servant to take a wife for his son, he portrayed an image of God the Father. Just as when he offered the boy as a holocaust, he then presented an image of God the Father, so also his servant signified the words of prophecy. For this reason Abraham sent his servant into a distant land to take a wife for his son, because God the Father intended to send his prophetic word throughout the world to search for the Catholic church as a spouse for his onlybegotten Son.
By this. He chose a mark which would manifest the kindness and humility of the maid, who would be a fit match for the pious Isaac. This was no vain observation. God heard his fervent prayer. (St. Chrysostom) (Calmet)
It is sometimes lawful to ask a sign or miracle of God, (Acts i. 24; iv. 30; 1 Kings xiv,) but we must carefully avoid whatever the Church disapproves. (St. Augustine de Gen. ii. 17; xii. 22.) (Worthington)