What is the ruling on a ring worn on the the forefinger (finger used for testifying to God's oneness) and upon which Surat Al-Qadr is recited to know the unseen, and what is the ruling on the one who wears it?

Knowledge of the Unseen is something Allah has exclusively reserved for Himself. Allah may reveal some of it to certain of His awliya' (saints), but not by their will, and a wali does not claim knowledge of the Unseen. The sign of a wali is their piety towards Allah and faith in Him. Anyone who deviates from the methodology and Sunnah of the Prophet, peace and blessings be upon him, is not a wali. What was mentioned about the ring and its owner pertains to soothsaying and divination, both of which are prohibited, and whoever engages in such practices or claims knowledge of the Unseen is included in the warnings (of punishment). Reciting Surat Al-Qadr over the ring does not change anything of this, as soothsayers may recite some Quran to deceive people.