When his wet-nurse, Halima al-Sa‘dia, first saw him, she laid her hand on him and he smiled. "When he smiled," she said, "a light appeared from his mouth that rose to the sky."[32. Bayhaqi, Abu Nu'aym, ibn Ishaq and Abu Ya'la.]
Some of the hadiths we have quoted here have strong chains of transmission, others have weaker ones. However, we must remember that even the chain considered weakest by Muslim traditionists, is quite acceptable as historical proof to any professional historian on this planet, being far stronger and better authenticated than other ancient sources he works with. It is also well known that weak traditions strengthen each other so as to become acceptable. This is why those we have quoted here have been accepted by leading scholars such as Ibn Kathir, Suyutiī, Qadi ‘Iyad, Bayhaqi, and others.
Commenting on the verse of Qur’an,"There has come to you a light from Allah and a clear Book,"[33. Qur'an (5:15)] the well-known scholar al-Alusi says that the light in question is no other than the Prophet, may Allah’s blessings and peace be upon him. He quotes the Follower, Qatada, as an authoritative source for this opinion, as well as other well known scholars, pointing out that this is the most logical interpretation of the construction of the verse, Then he also quotes those whose opinion differs from his in that they believe that both the light and the Book refer to the Qur’an. This he does because real Muslim scholars, as opposed to pretenders and impostors, always quote, along with their own opinions, the contrary opinions of other reputable scholars, so weighing both in the most objective manner. Qadi ‘Iyad, the famous author of al-Shifa’, is of the same opinion as al-Alusi, an opinion, an opinion shared by other famous commentators such as Tabari and Qurtubi.