12.How long were these Levitical ordinances to be maintained?

Until the time of reformation, of setting things right.

They were to remain in force until Christ came, the High Priest of the good things God has promised.

Wherefore then serveth the law? It was added because of transgressions, till the seed should come to whom the promise was made; and it was ordained by angels in the hand of a mediator (Galatians 3:19).