Dyeing hair in early versus established Islam
Nahj al-Balāgha|Volume 1|Book 3|Chapter 17
١٧. وَسُئِلَ (عليه السلام) عَنْ قَوْلِ الرَّسُولِ (صلى الله عليه وآله وسلم): غَيِّرُوا الشَّيْبَ وَلَا تَشَبَّهُوا بِالْيَهُودِ. فَقَالَ (عليه السلام):
17. Amīr al-mu’minīn, peace be upon him, was asked to explain the saying of the Messenger of Allāh: “Banish your old age (by hair-dye) and do not acquire resemblance to the Jews.” Amīr al-mu’minīn replied:
إِنَّمَا قَالَ (صلى الله عليه وآله وسلم) ذَلِكَ وَالدِّينُ قُلٌّ فَأَمَّا الْآنَ وَقَدِ اتَّسَعَ نِطَاقُهُ وَضَرَبَ بِجِرَانِهِ فَامْرُؤٌ وَمَا اخْتَارَ.
The Prophet صلى الله عليه وعلى آله وسلم said this at a time when the religion was confined to a few, but now that its expanse has widened and it is firmly settled everyone is free in his action. [1]