All commandments are immune to the effect of other commandments except their own
Handpicked by the Demon King himself, each member possesses a Commandment「戒禁 Kaigon」, a unique power gifted to them by the Demon King, which delivers a unique curse to whomever breaks a rule specific to each member. This power is absolute; it cannot be opposed even by its wielder, although members of the Ten Commandments are immune to all other Commandments except for their own. The curses will only be lifted if the victim defeats its wielder or at the victim's death.
Source - https://nanatsu-no-taizai.fandom.com/wiki/Ten_Commandments