Did any Israelites before Moses know by faith that God would deliver His covenant people?
Yes. Joseph knew by faith that God would take him back to Palestine, and Moses' parents knew by faith God was still in their midst. The context says some Israelites, not all, had known by faith that these things would happen to God's covenant people.
Les teaches that Joseph had sworn God would surely visit Israel and that they would carry his bones away with them, so Moses took Joseph's bones along. Les explains that many writers and historians leave out the miraculous and supernatural and wonder how these events came to be, but some of the people, not all, had known by faith that these things would happen to God's covenant people. Joseph knew the time was coming when God would take him back up to Palestine. Moses' parents, when they saw he was a proper child, knew by faith that God was still in their midst. Even as Moses and Aaron prepared to move the children of Israel out of Egypt, they knew they were going to Palestine, and so they took Joseph's bones with them.
More Questions
How did some of the Israelites know that God's promises would come to pass for His covenant people?
Some of the Israelites (not all) had known by faith that these things would happen to God's covenant people.