Did you make a promise to uphold this sacrifice, either to yourself or to God? By “promise” I don’t mean that you said or thought the particular words, “I promise…” I mean did you somehow make a firm resolution? Either to yourself or to God?
You may not morally forfeit a promise (provided the promise itself is not immoral), even if it is a promise made to yourself, without compelling cause (and a weakness of the will is not normally considered a compelling cause).
God expects us to be honorable in our promises - even (and especially) in promises made to ourselves. Think about it: if we cannot trust a promise we make to ourselves, how could we expect ANYBODY to trust a promise made to them?
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