Divine law is any law that comes directly from the will of God, in contrast to man-made law. Like natural law (which may be seen as a manifestation of divine law) it is independent of the will of man, who cannot change it. However it may be revealed or not, so it may change in human perception in time through new revelation. Divine law is commonly equated with eternal law, meaning that if God is infinite, then his law must also be infinite and eternal.
In Thomas Aquinas's Treatise on Law, divine law, as opposed to natural law, comes only from revelation or scripture, hence biblical law, and is necessary for human salvation. According to Aquinas, divine law must not be confused with natural law. Divine law is mainly and mostly natural law, but it can also be positive law.