Its summary is that “There is no contagion” is upon its apparent meaning, and that the command to flee from the leper is carried upon recommendation...

What is the ruling on instituting secular laws? And is it permissible to act by them? And does a ruler become a disbeliever by instituting these laws?

The one who banishes the Shari’ah entirely and puts another law in its place, that this indicates that he views the [secular] law to be better than the Sharīʿah...

Is there a difference between a specific issue in which the qāḍī (judge) passes judgement with other than what Allāh revealed and between issues that are considered general legislation.

Shaykh Ibn ʿUthaymīn clarifies his position on the issue of the rulers instituting secular laws, replacing the Sharīʿah with them and when takfīr can be made of them.

Those who follow the secular laws which Shayṭān has legislated upon the tongues of his allies, in opposition to what Allāh, the Majestic and Elevated...

This is a quote from Aḥkām al-Qurʾān of al-Qāḍī Bakr bin ʿAlā al-Qushayrī al-Mālikī (d. 344H). Though the translation is accurate enough, the context is missing.

The following statement has been ascribed to Ibn Hajar [rh] and is claimed to be in the 13th volume of the Maktabah Salafiyyah print of Fatḥ al-Bārī...