It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that he said: "When the Messenger of Allah (peace and blessings be upon him) spoke, (something) like light was seen coming out from between his (peace and blessings be upon him) front teeth."
This hadith is not narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) except with this chain and by this route, and Ibrahim bin al-Mundhir (may Allah have mercy on him) is alone in narrating it.
Hadith Referenceالمعجم الأوسط / باب الألف / 767
Hadith Takhrij«أخرجه الضياء المقدسي فى «الأحاديث المختارة» برقم: 70، 71، والدارمي فى «مسنده» برقم: 59، والترمذي فى «الشمائل» برقم: 15، والطبراني فى «الكبير» برقم: 12181»