God does not Speak Futile Things
“And he told him to go outside and said: Look to the sky and count the stars; can you count them? And he said to him: So shall your offspring be. “
We see here again that the temptation that struck and tortured the holy man, Abraham, cannot have been insignificant since God addresses and comforts him with so many words and even adds a sign. For God does not speak futile things. We can assume that it would have been sufficient that the promise concerning a natural son, born of his body, was given in such a clear and obvious manner, but now the Lord also adds a sign, tells him to go outside, look up to the sky, and count the stars; then he promises him a family of countless members…We should fairly esteem highly this text because God here talks so much to Abraham. For he does not speak to him any different than a friend speaks to his well-known friend. And this is how God usually does it, and it is his way, that he, once he has sufficiently saddened those who are his, deals with them in the kindest manner and pours himself out to them completely. The fact that he tells Abraham to count the starts indicates that such vision occurred to Abraham at night when he perhaps lay awake sighing and weeping. For this is what such high temptations do usually: they sneak up on hearts when they are by themselves. This is why Scripture often mentions nightly and solitary prayers whose master is temptation…Although this vision took place at night, it was not a dream but something real. For Abraham heard the voice of the Lord, went out of his room, stood under the open sky, and looked at the stars how they twinkled and shone, and then he finally heard the promise concerning his countless offspring and family…There is a difference between this and the previous promise made to Abraham, that his family should be like the sand of the sea. For Moses hereby indicates that this promise aims at the spiritual and heavenly offspring, while he only spoke of the bodily offspring above.
St. Louis ed., 1:938-940.