Is the hadith that states that reciting Ayat al-Kursi and dedicating its reward to the deceased causes Allah to place forty lights in the grave of every believer from east to west, expands their resting places, grants the reciter the reward of sixty prophets, raises their rank by one degree for each deceased person, and records ten good deeds for them – is this hadith authentic?

This hadith was narrated by Al-Daylami in Al-Firdaws with the wording: "There is no believing man or woman who recites Ayat al-Kursi and dedicates its reward to the people of the graves, but that Allah will not leave a single grave on the face of the earth without filling it with light, expanding its grave from east to west, granting him (the reciter) ten good deeds for every angel in the heavens, and Allah will record for the reciter the reward of seventy martyrs." Al-Firdaws by Al-Daylami is among the books that scholars of hadith terminology mentioned as sources of weak narrations. Ibn Iraq mentioned it in Tanzih al-Shariah and attributed it to Al-Daylami, stating that it was narrated through Ali ibn Uthman al-Ashajj, and Al-Dhahabi mentioned Uthman al-Ashajj in Al-Mizan as a liar. Thus, the invalidity of the hadith is known.