Why on Friday night do we say “Spread over us Your shelter of peace” instead of “Who guards His people Israel forever”?

This source-based Hagut Yosef essay explores the question: Why on Friday night do we say “Spread over us Your shelter of peace” instead of “Who guards His people Israel forever”? The canonical Hebrew article develops the theme through Torah sources and reflection on human life. This localized discovery layer preserves the source’s meaning and identity and does not add new halakhic, historical, psychological, medical, legal, political, scientific, or empirical claims beyond the Hebrew source.