Is the saying "The abnormal person has no حكم (ruling) concerning him" correct and attributed to Ibn Taymiyyah, and what does it mean?

The phrase attributed to Ibn Taymiyyah was not found. However, it is known that jurisprudential rulings are based on what is common, not on what is rare, as the rare is considered almost non-existent. Sometimes, rulings are based on the anomalous and rare out of mercy for the servants of Allah.