What is the concept of Jihad and martyrdom linguistically and Islamically, what are the ranks and types of martyrs, what is the life of martyrs like with their Lord, and what is the effect of the Imam's permission on declaring Jihad?

Linguistically, Jihad means expending one's utmost effort and energy, whether in word or deed. Islamically, it is the exertion of effort by Muslims in fighting disbelievers to uphold the word of Allah. As for Shahada, linguistically it means definitive news, presence, direct observation, and death in the path of Allah. Islamically, it is dying while fighting disbelievers for His sake. In matters of the afterlife, other types of martyrs are included with them.

Martyrs are divided into three categories: 1. One who is killed in a war against disbelievers: He is treated as a martyr in the afterlife and in this world (he is not washed nor prayed over). 2. Martyr of reward: Such as one who dies from an abdominal disease, or plague, or under rubble. He is washed and prayed over, and he receives the reward of martyrs in the afterlife. 3. One who embezzles from war spoils and is then killed in a war against disbelievers: He is treated as a martyr in this world (he is not washed nor prayed over), but he does not receive the full reward of martyrs in the afterlife.

The rank of martyrs is great, second only to that of prophets, the truthful, and the righteous. They vary in their stations in Paradise. Among the best of them is one who fights the enemy without turning back until he is killed. One who is killed while striving with his life and wealth in the path of Allah has his sins forgiven. The master of martyrs is Hamza ibn Abd al-Muttalib, and the man who stands up to an oppressive ruler, commands him to do good, forbids him from evil, and is then killed by him.

The life of martyrs is an intermediary one with their Lord, where they are honored with the blessings of Paradise and provided for. Allah has placed their souls in the gizzards of green birds that roam freely in Paradise.

Jihad becomes an individual obligation (fard ayn) if disbelievers attack Muslims. In such a case, the permission of the Imam is not required. However, for Jihad intended for conquest and spreading Islam, the Imam's permission is necessary.