Ibn Sirin محمد بن سيرين الأنصاري · The Book on Virtues of Jihad

That the Messenger of Allah (ﷺ) said: "Whoever develops some gray hair in the cause of Allah, it shall be a light for him in the Day of Judgement. This Hadith is Hasan Sahih Gharib. As for Haiwah bin Shuraih, (the remainder of his name is) Ibn Yazid Al-Himsi.