Dante's Divine Comedy is divided into three sections: Hell, Purgatory and Paradise. Each section is further divided into 33 poems (called cantos). Dante meets three beasts, Satan has three mouths, and three is a symbolic number in Christian theology for the Trinity - the three parts of the Godhead: Father, Son and Holy Spirit. The three major types of sin are incontinence, violence, and fraud. The hound that guards the gates of hell, Cerberus, has three heads. There are many other important "3s".
Hell is divided into nine circles which each represent a different type of sin (nine is the square root of three). The circles are sub-divided into upper and lower circles and circle number 8 is sub-divided into 10 types of frauds. Dante believed that fraud was a sin that could only be committed by man, so therefore God hated fraud more than anything else. Fraud included panderers, flatterers, corrupt church practices (having to pay for receiving the sacraments of the church), sorcery, etc.
Ten is a number of completeness or perfection in the Bible. The number of "canti" in the poem is 100, the square of the perfect number, 10. There are 10 commandments, there were 10 plagues sent by God to punish Egypt, and the Anti-Christ's realm is predicted to consist of 10 kingdoms, among many other significant illustrations of this perfect number.
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