Full Idea
Everyone regards moral laws as commands, which they could not be if they did not connect consequences with their rule a priori, and thus carry with them promises and threats, which must lie in a necessary being as the highest good.
Gist of Idea
Moral laws are commands, which must involve promises and threats, which only God could provide
Source
Immanuel Kant (Critique of Pure Reason [1781], B839/A811)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.680
A Reaction
This reveals the thinking of Kant's moral argument for God rather more nakedly than elsewhere.