Bukhari

Hadith Commentary:
In the era of ignorance (Jahiliyyah), swords used to be adorned with gold and silver.
The Muslims, disregarding outward adornment, embellished and enhanced their swords with lead and iron, for in reality, this was their true adornment.
Even today, it is the custom of all civilized nations of the world to maintain instruments of war in the best possible condition.

Hadith Commentary:
In one narration, the background of this hadith is described in these words: A victorious nation under the leadership of Sulaiman bin Habib came to Abu Umamah (radi Allahu anhu), and there was a desire for the silver on their swords.
Abu Umamah (radi Allahu anhu) became very displeased upon seeing them and narrated this hadith.
(Sunan Ibn Majah, Al-Jihad, Hadith: 2807)
In the era of ignorance (Jahiliyyah), people would adorn their swords with gold and silver as a matter of pride and boasting. The Muslims, disregarding outward adornment, would decorate and artificially enhance their swords with lead and iron.
Even today, it is the custom of nations around the world to keep their weapons of war in the best possible condition.
The noble Companions (radi Allahu anhum) were indifferent even to this, because despite being few in number, they would prevail over their enemies due to the strength of their faith (iman); they had no need for any artificial power.