Commercial, Family, and Criminal Law Sections

The sections of As-Sunan al-Kubra dealing with commercial law, family relations, and criminal justice represent the full breadth of al-Bayhaqi's coverage of Islamic jurisprudence. The commercial sections address the legal requirements for valid sales, the conditions that invalidate contracts, the prohibition of usury and excessive uncertainty, and the specific rulings on various types of commercial arrangements such as partnership, leasing, and advance purchase. Al-Bayhaqi presents the hadith evidence for these rulings with his characteristic combination of authentication assessment and legal analysis.

The family law sections cover the full range of Islamic domestic law: marriage and its conditions, the rights and obligations of the spouses, the various forms of divorce and their consequences, the waiting period, custody of children after divorce, and the financial obligations that persist after dissolution of the marriage. These sections are extensively developed and represent a comprehensive presentation of Shafi'i family law grounded in authenticated hadith evidence. The detailed citations from the Companions and early jurists alongside the prophetic traditions make these chapters valuable for scholars working on the history of Islamic family law.

The inheritance sections present the complex calculations of Islamic inheritance law through the hadith evidence that underlies each ruling. Al-Bayhaqi's authentication work in these chapters is particularly important because inheritance law depends on a relatively small number of key traditions whose reliability is foundational to the entire system. His careful assessment of the chains bearing on inheritance rulings has been regularly cited by subsequent scholars as authoritative guidance.

The criminal law sections cover the fixed penalties for serious crimes, the conditions for their application, and the evidentiary requirements of Islamic criminal procedure. Al-Bayhaqi's presentation emphasizes the stringent requirements for establishing guilt in capital and corporal cases, reflecting the Shafi'i understanding that the prophetic tradition intended these penalties to be rarely applied in practice while remaining theoretically in force as expressions of divine law.