(Verse 17) - The time of the promise - The time of the “fulfillment” of the promise.

The people grew  - Exo. 1:7-9.

(Verse 18) - Till another king arose - This is quoted from Exo. 1:8. What was the “name” of this king is not certainly known. The “common” name of all the kings of Egypt was “Pharaoh,” as “Caesar” became the common name of the emperors of Rome after the time of Julius Caesar: thus we say, Augustus Caesar, Tiberius Caesar, etc. It has commonly been supposed to have been the celebrated Rameses, the sixth king of the eighteenth dynasty, and the event is supposed to have occurred about 1559 years before the Christian era. One historian supposes that his name was Mandonei, whose reign commenced in 1585 B.C., and ended 1565 years before Christ. Another supposes that it was Amosis, or Ames, the “first” king of the eighteenth dynasty. “The present knowledge of Egyptian history is too imperfect to enable us to determine this point”.  We should note this is a matter of little import to Bible students, but of great import to those who see error and contradiction in the Bible.  The truth of the matter is that we simply do not know what the name of the Pharaoh of Moses’ time was one way or the other.

Which knew not Joseph - It can hardly be supposed that he would be ignorant of the name and deeds of Joseph; and this expression, therefore, probably means that he did not favor the designs of Joseph; he did not remember the benefits which he had conferred on the nation; or furnish the patronage for the kindred of Joseph which had been secured for them by Joseph under a former reign. National ingratitude has not been uncommon in the world, and a change of dynasty has often obliterated all memory of former obligations and compacts.

(Verse 19) - Dealt subtly - He acted deceitfully; he used fraud. The cunning or deceitful attempt which is referred to, is his endeavor to weaken and destroy the Jewish people by causing the midwives to cause their male children to be put to death, (Exo. 1:22).

Our kindred - Our nation, or our ancestors.

And evil-entreated - Was unjust and cruel toward them.

So that  - For that purpose, or to “cause” them to cast them out. He dealt with them in this cruel manner, hoping that the Israelites themselves would destroy their own sons, that they might not grow up to experience the same sufferings as their fathers had. The cunning or subtlety of Pharaoh extended to everything that he did to oppress, to keep under, and to destroy the children of Israel.