Must? Aren't you a gnostic? The first rule of gnosticism: You don't know what you don't know. Your ignorance is showing.
Why in the world would you apply this level of certainty to Jewish law? You clearly don't know it. And. AND. It's so easy to check.
Exodus 12:24
ושמרתם את־הדבר הזה לחק־לך ולבניך עד־עולם׃
And you shall observe this thing for an ordinance to you and to your sons forever.
Leviticus 7:34
אשר צוה יהוה לתת להם ביום משחו אתם מאת בני ישראל חקת עולם לדרתם׃
Which the Lord commanded to be given to them by the people of Israel, in the day that he anointed them, by a statute forever throughout their generations.
Levviticus 23:31
כל־מלאכה לא תעשו חקת עולם לדרתיכם בכל משבתיכם׃
You shall do no kind of work; it shall be a statute forever throughout your generations in all your dwellings.
Then you would also be 100% wrong perr scripture. Hopefully you and the Gnostic with KNOW better next time.