Are Sufi terms such as: al-maʿrifah (gnosis), al-tajrīd (detachment), and al-tafrīd (isolation) sound, knowing that they were not mentioned in the sayings of the Companions?

The ruling on words is determined by their meaning and the speaker's intent. The three terms (ma'rifah [gnosis], ilm [knowledge], and aql [intellect]) were considered by Al-Harawi in his Nihayat Manazil As-Sa'irin as high stations. Ibn Al-Qayyim expounded on them in Al-Madarij, clarifying the right and wrong perspectives, explaining the difference between ilm and marifah. He stated that Allah chose for Himself the name Al-Alim (The Knower) because its application is broader, and that the term ma'rifah (gnosis) appeared in the Qur'an specifically in reference to the believers among the People of the Book.