A kāhin and an ʿarrāf are terms relating to claimed knowledge of hidden matters; their particular practices may differ. Such claims are not put on the level of reliable revelation.
A serious prophetic warning is transmitted concerning consulting a diviner. Astrological conjecture, claims about hidden events, and Allah's knowledge of the unseen must not be conflated.
Individual claims do not become religious proof against the Qurʾan, Sunnah, and reliable consensus.