Imam Ali (AS) said:

Where are the people who were invited to and accepted Islam, recited the Quran and understood the meaning of Ayahs (verses), they faced Jihad with eagerness like a camel going to her child, they were inspired with Jihad. They pulled out the swords from sheaths and surrounded the earth group after group. Some were martyred and some were saved, never were they happy to remain alive in the battlefield, and they did not need to be condoled for the martyrs. Their eyes were in pain due to long periods of crying from fear of God, and their stomachs stuck to their backs due to constant fasting. Their lips were dry by constantly reciting Dua, and the colour of their faces turned yellow due to staying awake at nights for worshipping God, and the haze of humbleness covered their faces. They are my brothers who have gone, and it is our duty to be eager to meet them, and with the anguish of being separated from them, bite our fingers with regret [1].

[1] Nahjul Balaghah, Sermon 121.

Source: en.shafaqna.com