This book argues for the use of Old Testament ethical principles in entrenching constitutionalism in democratic Malawi. This posture is against the background of the already existing sections 12 and 13 of Malawi's Constitution which have moral underpinnings. Using the theories of Divine Command and Deontology, the study discusses ten critical Old Testament ethical principles and elucidate why and how they can be used to entrench constitutionalism in Malawi. The study demonstrates that the giving of the law to Israel was God's model for (codified) national constitutions, aiming at envisioning and entrenching constitutionalism through the principle of justice which apparently, is the heartbeat of the Old Testament ethics and morality. Therefore, to some extent, constitutionalism in Malawi can be entrenched by pursuing justice and protecting its integrity. Very relevant is the study's emphasis that the Decalogue is a Magna Carta for human rights and freedoms. Pertinent also is the scriptural analysis which shows that the threefold nature of government is intrinsically theological as the study's findings demonstrate. These Old Testament study findings show that no one, not even the president, is above the law--thus demonstrating limited governmental powers, separation of powers, accountability, respect for human rights, and rule of law where everyone is under the law and correctable by it. The study's original contribution is in its demonstration that Old Testament ethical principles are the foundation of constitutionalism by showing the theological basis of constitutionalism's tenets of limited government, separation of powers, rule of law, human rights, and accountability. Consequently, the original contribution of this study to the academia is its blending of theological and jurisprudential discourse on good governance based on Old Testament ethical principles and moral values in entrenching constitutionalism in Malawi.