Abu Najih as-Sulami told that he heard God’s Messenger say, “He who causes an arrow to hit its mark in God’s path will have it count as a degree for him in paradise, if anyone shoots an arrow in God’s path it is equivalent to his setting someone free, and if anyone develops a grey hair on behalf of Islam it will be a light for him on the day of resurrection." Baihaqi transmitted it in Shu'ab al-iman. Abu Dawud transmitted the first section, Nasa’i the first and second, and Tirmidhi the second and third. The version of Nasa’i and Tirmidhi has, “If anyone develops a grey hair in God’s path,” instead of “on behalf of Islam."
Hadith Referenceمشكوة المصابيح / كتاب الجهاد / 3873
Hadith Gradingالألبانی:صَحِيح | زبیر علی زئی:إسناده صحيح
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «إسناده صحيح، رواه البيھقي في شعب الإيمان (4341) وأبو داود (3965) و النسائي (26/6. 27 ح 3145) و الترمذي (1638 وقال: حسن صحيح)»