In process of time. Literally, "in those many days." The reign of Rameses II. was exceptionally long, as previously explained. He had already reigned twenty-seven years when Moses fled from him (Exodus 2:15).
He had now reigned sixty-seven, and Moses was eighty! It had seemed a weary while to wait. The children of Israel sighed. If the time had seemed a weary while to Moses, how much more to his nation! He had escaped and was in Midian — they toiled on in Egypt.
He kept sheep — they had their lives made "bitter" for them "with hard bondage, in molter, and in brick, and in all manner of service in the field" (Exodus 1:14). He could bring up his sons in safety; their sons were still thrown into the river.
No wonder that "an exceeding bitter cry" went up to God from the oppressed people, so soon as they found that they had nothing to hope from the new king.