(Arabic, derived from the root na-ba-’a meaning ‘to utter’ or ‘to inform’), also ta-na-ba-’a to claim for oneself the gift of prophecy or office of a prophet. Hence, nubuwwa means prophethood. It is a definitive aspect of Muslim religious belief, being the primary means by which God communicates to humankind. Nubuwwa is a rich and central topic in the Qur'an which refers to a continuous chain of revelation-bearers who were related genealogically. According to the Quran, this chain starts with Adam, and ends with the khatam al-anbiya’ (the seal of Prophets), that is, Prophet Muhammad. Theologians developed a theory of the distinctive signs of prophethood (dala’il, ‘alamat, or imarat al-nubuwwa). These included receiving the revelation (wahy), that the Prophet is of a noble descent, having a mark between his shoulders, having miraculous powers, and being supported with marvels which prove his status. By the 13th century, theologians went on to develop the doctrine of ‘isma (infallibility/impeccability) as a fundamental sign of nubuwwa and this was applied broadly to Prophet Muhammad.