Set the ancient egyptian god of destruction did not rip himself out. the most popular myth is this: when nut the goddess of the sky became pregnant the sky god Ra fearing an overthrow of his power cursed her so she couldn't have kids during the 360 day year so nut went to Thoth the god of wisdom and through a series of contest added 5 extra days to the year and during those five days she had five children, Nethpys, Horus, Osiris, Isis and Set.

Sorry for the long explanation but I hope this helps.

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