Exodus 1:19

On the midwives' lie, by which they deceived Pharaoh and kept him from killing the Israelite males when they were born: The midwives said that Hebrew women did not give birth as Egyptian women did. It is usual to ask whether such lies have been approved by divine authority. Scripture says that God favored the midwives. It is unclear whether God, in his mercy, pardoned the lie or judged that the lie itself deserved a reward. For the midwives did one thing by letting the infant boys live and another by lying to Pharaoh. In letting them live they performed a work of mercy; but they used that lie for their own ends, to keep Pharaoh from harming the infants. This act could be the occasion not for praise but for pardon. It does not seem to me that the authority to lie has been given to those of whom it is said, "And a lie has not been found in their mouths." For if the lives of certain people, being far below the level of the saints' lives, include these sins of lying, these people are living in accord with their natural abilities, especially if they do not yet know that they should expect heavenly gifts but busy themselves with earthly things. As for those who live in such a way that their conversation, as the apostle says, is in heaven, I do not think that they should regulate the style of their speech, insofar as it affects speaking the truth and avoiding falsehood, on the example of the midwives. But we should consider this question more carefully, on account of the other examples that are found in Scripture.

Many lies indeed seem to be for someone's safety or advantage, spoken not in malice but in kindness: such was that of those midwives in Exodus, who gave a false report to Pharaoh, to the end that the infants of the children of Israel might not be slain. But even these are praised not for the fact but for the disposition shown; since those who only lie in this way will attain in time to a freedom from all lying.

Indeed, in regard to other Hebrew women you find it written that the Hebrew women give birth before the midwives arrive. This is so because the souls of the just do not wait upon branches of learning arranged according to kinds of knowledge, nor do they require assistance in parturition, but they bring forth their offspring spontaneously and anticipate the expected time.

And the midwives said unto Pharaoh, because the Hebrew women are not as the Egyptian women,....

Some of the ancient Jews expound it thus, Ere the midwife comes to them they pray to their Father in heaven, and he answereth them, and they do bring forth. Note, God is a readier help to his people in distress than any other helpers are, and often anticipates them with the blessings of his goodness; such deliverances lay them under peculiarly strong obligations.