The "elaboration of the theories" of naskh can be dated with certainty to the last half of the second century of Islam, when Imam Shafi'i (d.204 AH/820), in his work "Risāla", (and in the somewhat later "Ikhtilāf al-Hadīth"") worked to resolve the "apparent discrepancies between certain Qur'ānic verses and others; between certain "hadith" and others; and, most serious of all, between certain Qur'ānic verses and certain "hadīths"", according to John Burton. Ibrahim al-Nakha'i (d. 96/714) is reported to have said that verse Q.5:106 was abrogated