Matthew Poole and continuators on Exodus 1:15

15 And the king of Egypt spake to the Hebrew midwives , (of which the name of one was Shiphrah, and the name of the other Puah.)

Such as not onely were employed about the Hebrew women, but were Hebrews themselves, not Egyptians, as some suppose, as may appear, 1. because they are expresly called not the midwives of the Hebrews, but the Hebrew midwives. 2. the Egyptian midwives would not willingly employ their time and pains among the meanest and poorest of servants, as these were. And if they were sent in design by the King, he had lost his end, which was to cover his cruelty with cunning, and to perswade the people that their death was not from his intention, but from the chances and dangers of child-bearing. 3. the Hebrew women as they had doubtless midwives of their own, so they would never have admitted others. 4. they are said to fear God, ver. 17. 21.

You are not to think that these were the onely midwives to so many thousands of Hebrew women, but they were the most eminent among them, and it may be for their excellency in that profession called to the service of some Egyptian Ladies, and by them known to Pharaoh, who might therefore think by their own interest and by the promise of great rewards or by severe threatnings to oblige them to comply with his desires; and if he met with the desired success by them, he meant to proceed further and to engage the rest in like manner.