וְאִ֛ם הֵאָכֹ֥ל יֵאָכֵ֖ל בַּיּ֣וֹם הַשְּׁלִישִׁ֑י פִּגּ֥וּל ה֖וּא לֹ֥א יֵרָצֶֽה׃
And if it be eaten at all on the third day, it is a vile thing; it shall not be accepted.
Read kabbalistic (mystical) interpretation of Leviticus 19:7: and classical mystical sources.