Genesis 25:21

21.And Isaac entreated the Lord for his wife. Some translate the passage, Isaac entreated the Lord in the presence of his wife; and understand this to have been done, that she also might add her prayers, and they might jointly supplicate God. But the version here given is more simple. Moreover, this resort to prayer testifies that Isaac knew that he was deprived of children, because God had not blessed him. He also knew that fruitfulness was a special gift of God. For although the favor of obtaining offspring was widely diffused over the whole human race, when God uttered the words “increase and multiply;” yet to show that men are not born fortuitously, he distributes this power of production in various degrees. Isaac, therefore, acknowledges, that the blessing, which was not at man’s disposal, must be sought for by prayer from God. It now truly appears, that he was endued with no ordinary constancy of faith. Forasmuch as the covenant of God was known to him, he earnestly (if ever any did) desired seed. It, therefore, had not now, for the first time, entered into his mind to pray, seeing that for more than twenty years he had been disappointed of his hope. Hence, although Moses, only in a single word, says that he had obtained offspring by his prayers to God; yet reason dictates that these prayers had continued through many years. The patience of the holy man is herein conspicuous, that while he seems in vain to pour forth his wishes into the air, he still does not remit the ardor of his devotion. And as Isaac teaches us, by his example, to persevere in prayer; so God also shows that he never turns a deaf ear to the wishes of his faithful people, although he may long defer the answer.