Definition and Scope:
In biblical terms, a command or regulation refers to a directive or rule given by God, often through His prophets or directly through Scripture, that is intended to guide the moral, spiritual, and communal life of His people. Commands are integral to the covenant relationship between God and humanity, serving as expressions of His will and character.

Old Testament Context:
The concept of divine commands is foundational in the Old Testament, particularly within the Pentateuch. The most prominent example is the Ten Commandments, delivered to Moses on Mount Sinai, as recorded in Exodus 20:1-17 and Deuteronomy 5:6-21. These commandments form the core of the Mosaic Law, encompassing duties to God and fellow humans.

Commands in the Old Testament are not limited to the Decalogue but extend to various laws covering ceremonial, civil, and moral aspects of life. Leviticus, Numbers, and Deuteronomy contain numerous regulations concerning worship, dietary laws, social justice, and personal conduct. For instance, Leviticus 19:18 instructs, "Do not seek revenge or bear a grudge against any of your people, but love your neighbor as yourself. I am the LORD."

New Testament Context:
In the New Testament, Jesus Christ affirms and fulfills the law, emphasizing the spirit rather than the letter of the commands. In Matthew 22:37-40, Jesus summarizes the law with two great commandments: "‘Love the Lord your God with all your heart and with all your soul and with all your mind.’ This is the first and greatest commandment. And the second is like it: ‘Love your neighbor as yourself.’ All the Law and the Prophets hang on these two commandments."

The apostolic writings further expound on the nature of commands under the New Covenant. The Apostle Paul, in Romans 13:9-10, reiterates the essence of the law as love: "The commandments, ‘Do not commit adultery,’ ‘Do not murder,’ ‘Do not steal,’ ‘Do not covet,’ and whatever other commandment there may be, are summed up in this one command: ‘Love your neighbor as yourself.’ Love does no wrong to its neighbor. Therefore love is the fulfillment of the law."

Purpose and Function:
Commands serve multiple purposes in Scripture. They reveal God's holiness and righteousness, setting a standard for His people to emulate. They also function as a means of sanctification, guiding believers in living a life pleasing to God. Moreover, commands are designed to foster community and justice, ensuring that relationships among individuals and with God are maintained in harmony.

Theological Implications:
Theologically, commands underscore the covenantal relationship between God and His people. Obedience to God's commands is a response to His grace and a demonstration of faith. In the New Testament, the indwelling of the Holy Spirit empowers believers to live according to God's commands, as seen in Romans 8:4, "so that the righteous requirement of the law might be fulfilled in us, who do not walk according to the flesh but according to the Spirit."

Practical Application:
For contemporary believers, commands remain relevant as they reflect the unchanging moral character of God. While the ceremonial and civil laws specific to Israel are not binding under the New Covenant, the moral imperatives continue to guide Christian ethics. Believers are called to study Scripture diligently, seeking to understand and apply God's commands in their daily lives, as encouraged in 2 Timothy 3:16-17: "All Scripture is God-breathed and is useful for instruction, for conviction, for correction, and for training in righteousness, so that the man of God may be complete, fully equipped for every good work."