According to the consensus of classical Islamic scholarship, the Quranic command in Surah Al-Ahzab, verse 5—'Call them by [the names of] their fathers; it is more just in the sight of Allah'—serves as the foundational principle for preserving lineage (nasab) in Islamic family law. Tafsir experts like Ibn Kathir and Al-Tabari explain that this verse directly abrogated the pre-Islamic custom of 'tabanni', where an adopted son would take the name and full legal status of the adopting father. The immediate historical context was the case of Zayd ibn Harithah, who was known as Zayd ibn Muhammad until this revelation, after which he was called by his biological father's name. Al-Qurtubi elaborates on the legal wisdom, noting that preserving lineage is crucial for matters of inheritance, marriage eligibility (mahram), and social clarity. This verse distinguishes the highly encouraged Islamic concept of guardianship (kafala)—caring for a child while preserving their identity—from the prohibited act of erasing their biological parentage. This ruling is not a discouragement of caring for orphans but a profound protection of a child's inherent right to their identity and heritage.