Fasting, similar to other actions in life, has specific purposes and appointed times. The Bible offers various reasons why people might fast: an immediate need in prayer (2 Samuel 12:16), a need to loosen the bands of wickedness or undo heavy burdens (Isaiah 58:6), during times of elevated conflict or duty in service (Matthew 17:21; Acts 13:3), as a symbol of mourning (2 Samuel 1:12), and as an outward manifestation of true repentance (Jonah 3:5). This list is not exhaustive, but simply demonstrates that God’s people have many good reasons for fasting. Even if none of these circumstances surfaces in our lives, we should fast because we know that the Lord expects us to do so.
Reading commentaries offers varying opinions concerning the definition of purity. However, the Bible offers some exacting details which give the right definition. Today's passage speaks of the “pure blood of the grape.” In other words, nothing was added to the juice—it was pure. There are several other substances in scripture identified as pure: gold (Exodus 25:39), olive oil (Exodus 27:20), myrrh (Exodus 30:23), incense (Exodus 37:29), and language (Zephaniah 3:9). Each instance emphasizes that nothing exists to corrupt the nature of the original. These substances are not combined with other materials to dilute or defile them. In essence, purity demands the absence of any substance that corrupts, defiles, or taints in any way.
