"He blessed them on that day, saying: may God make you like Ephraim and Manasseh" (Genesis 48:20). Rabbi Levi Yitzchak of Berditchev uses Jacob's blessing to explain a peculiar teaching from the Talmud: God's way of doing things is the opposite of the human way.
The Talmud (Megillah 15) says that a human being places a pot on the stove before filling it with water, but God pours the water first and then places the pot. The proof text is (Jeremiah 10:13): "When He makes His voice heard, there is a rumbling of water in the heavens." Water (the blessing) precedes the vessel (the preparation).
Rabbi Levi Yitzchak connects this to the verse, "All the diseases that I brought upon Egypt I will not bring upon you, for I am the Lord your healer" (Exodus 15:26). God describes Himself as our healer before any illness occurs. The healing is arranged before the affliction. When God brings suffering upon the righteous, the purpose is always constructive: to make the recipient aware of Who orchestrates the salvation.
The parable of the pot and water works like this: the disease or affliction is the "pot," the vessel that must be prepared. The healing and lovingkindness are the "water" that fills it. God supplies the refining materials first, and only then bestows the gifts, ensuring that the recipient is mature enough not to waste them. A small vessel must be broken before it can be reconstructed as a larger one.
This is why Jacob placed Ephraim, the younger brother, ahead of Manasseh, the elder. Ephraim would face greater suffering in the future, meaning he would undergo more refining. But that refining would prepare him to receive greater blessings. The one who suffers more is not cursed. He is being made into a bigger vessel.