Sunni Islam depends on the Companions in a way it does not always advertise: if their reports are unreliable, the hadith corpus collapses and with it most of the law. Hence the doctrine of ta'dil al-sahaba, the collective uprightness of the generation, which is a methodological necessity as much as a devotional stance. Shia Islam assesses them individually and finds many of them wanting, transmitting instead through the Imams — which is why the two traditions have almost entirely separate hadith collections. The cursing of the first three caliphs, sabb al-sahaba, has been criminalized in various Sunni states, and Shia jurists including Khamenei have issued rulings against insulting figures Sunnis revere. Aisha sits at the sharpest point of this: the Prophet's most beloved wife and a major jurist to Sunnis, and the woman who led an army against Ali to Shia. Her age at marriage, given as six or nine in Bukhari, is disputed on internal-chronology grounds by a growing number of Muslim scholars.