What does Genesis 45:18 mean?
Pharaoh, the monarch ruling over Egypt, had placed Joseph in the position of second-in-command (Genesis 41:44). When he learned Joseph had reunited with his estranged family (Genesis 45:1–2), he reacted with joy (Genesis 45:16). As soon as his identity was revealed, Joseph described a plan for the entire family to move to Egypt and live near to him to survive the ongoing famine (Genesis 45:10–11).Pharaoh favors Joseph highly, so he steps in to enhance this offer of hospitality. He promises to give to Joseph's extended family the best of the land of Egypt. Not only will they be cared for, but they will also be offered the best Egypt has to offer. This is far better than Jacob and his people could ever have hoped for. Instead of facing starvation, the Pharaoh of Egypt would see to it they would thrive.
Proverbs 21:1 says that a king's heart is a stream of water in the hand of the Lord. God turns it wherever He will. In this case, God has—among other things—prepared Pharaoh's heart. The Egyptian king's intent is to show favor to God's people, Israel. This will save them from a famine that would likely have wiped them out or scattered them.