Waqf (Ḥubus): a Millennial Institution between Canonical Inalienability, Governance Crisis and FinTech Revival for Sustainable Development

The waqf (or ḥubus) is a juridical-religious institution of Islam founded on the irrevocable and perpetual destination of a good (aṣl) for pious purposes, through the immobilisation of capital and the devolution of the fruits (manfaʿa). It embodies the highest form of permanent charity (ṣadaqah jāriyah), with normative roots in the act performed by ʿUmar ibn al-Khaṭṭāb at Khaybar (628 CE). Historically, the waqf has fulfilled a dual function, acting as a decentralised welfare provider that financed universities (Al-Azhar), hospitals (the Bīmāristān of Qalāwūn), and urban complexes (Süleymaniye), while also serving as an instrument of patrimonial engineering (waqf ahlī), which allowed elites to circumvent Qur'anic inheritance rules (farāʾiḍ) and preserve dynastic wealth. Its main strength, namely its canonical inalienability, which historically protected endowed assets from confiscation, also imposed macroeconomic constraints associated with illiquidity and allocative inefficiencies (the "Long Divergence": Kuran, 2011). Added to this is the structural weakness of governance: the information asymmetry and the chronic agency problem of the mutawallī (administrator). The reforms of the twentieth century responded with abolition (Tunisia, 1957) or centralisation (Egypt, Turkey). Today, the revival of the waqf takes place through innovation. Modern jurisprudence has expanded the institution of istibdāl (substitution) and legitimised corporate waqf. At the same time, FinTech technologies (blockchain, smart contracts, tokenisation of manfaʿa) offer solutions to reconcile perpetuity and liquidity, reduce information asymmetry and transform the waqf into a dynamic ethical fund, in line with at least seven Sustainable Development Goals. The digital waqf may therefore be interpreted as a potential institutional catalyst for Islamic economic adaptation in the twenty-first century.