Following a moment of intense anger and a harsh curse directed at Canaan, Noah experiences a profound emotional shift. Because the spirit of prophecy cannot rest upon a person consumed by rage, Noah must first calm down. Once he is at peace, a new prophetic vision begins, completely separate from the previous curse, shifting his focus to bless his son Shem [העמק דבר, קאסוטו, ביאור יש״ר, רש ר הירש].
Rather than addressing Shem directly, Noah opens with deep gratitude to God. The primary approach among commentators is that Noah is thanking God for guiding Shem to act with modesty and morality, while also praising God for the future promises He will fulfill through Shem's descendants. Directing the blessing toward God also serves to highlight Shem's absolute freedom. While Canaan is condemned to human servitude, Shem is blessed as a completely free man whose only master is God [בכור שור, חזקוני, הטור הארוך].
Noah specifically refers to God as the God of Shem. Commentators agree that this establishes a major historical prophecy. The true recognition of God, the resting of the Divine Presence, and the gift of prophecy would eventually become the unique heritage of Shem's descendants, the people of Israel. Just as God is later identified as the God of Abraham or the God of Israel, His name is permanently tied to Shem. It is Shem's descendants who are destined to serve God and teach faith to the entire world, standing in sharp contrast to the impulsive and materialistic worldview represented by Ham [רד״ק, רס״ג, אלשיך, רש ר הירש].
The resulting dynamic between the brothers dictates that Canaan will become a servant. The primary approach among commentators views this servitude as applying collectively to the future nations that will emerge from them, rather than to the men as private individuals [רש״י, רמב״ן, רש ר הירש, שטיינזלץ]. However, some suggest the subjugation applies directly to Shem alone [אבן עזרא], or equally to all of Canaan's brothers [שד״ל, ביאור יש״ר]. Throughout history, this subjugation materialized in various ways. It was realized during the Israelite conquest of the land of Canaan [רש״י, מזרחי, מלבי״ם], and later when the Gibeonites were made woodchoppers and water drawers for God's altar [ספורנו, חתם סופר]. It even occurred earlier in the days of Abraham, when Canaanite cities like Sodom and Gomorrah, which engaged in sins similar to Ham's, were conquered by Chedorlaomer, a descendant of Shem [קאסוטו].
Beyond the historical events, this servitude carries a deep spiritual purpose. It acts as an educational punishment for the severe disrespect shown to a parent [רס״ג]. By becoming subservient to the descendants of Shem, Canaan is brought into a structured framework of commandments, which ultimately serves as a spiritual repair for his original sin [חתם סופר]. Finally, these events offer a stark warning about the dangers of drunkenness. Even a perfectly righteous man like Noah, who saved the entire world, stumbled because of wine. This single loss of control led to deep personal disgrace and brought a lasting curse upon his descendants [רמב״ן, הטור הארוך].