Why does the Torah say that teshuvah is “not in heaven” but close to us, in our mouth and heart?

This source-based Hagut Yosef essay explores the question: Why does the Torah say that teshuvah is “not in heaven” but close to us, in our mouth and heart? 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.