Identical twins and a critical mistake: if pidyon haben was performed for the wrong child, can it remove the sanctity from the true firstborn?

This source-based Torah study examines the question: Identical twins and a critical mistake: if pidyon haben was performed for the wrong child, can it remove the sanctity from the true firstborn? The canonical Hebrew discussion develops the issue through the weekly Torah portion and the sources cited there, preserving the distinctions, tensions, and practical implications of the original text. This localized discovery layer does not add any new halakhic, medical, legal, scientific, historical, theological, or empirical ruling or claim beyond the canonical Hebrew source.