What are the conditions for choosing the people of "Ahl al-Hall wa al-'Aqd" (those who untie and bind/those who solve and sanction)? And who chooses them?

For the people of authority (Ahl al-Hall wal-Aqd), the following conditions are stipulated: justice, knowledge that enables them to understand the conditions of imamate, sound judgment and wisdom to choose the most suitable candidate, and that they possess influence (shawka). They must also be characterized by sincerity and good counsel towards Muslims.

They are appointed in two ways: either by the Caliph's designation, or by their presence (i.e., self-appointment through recognition) if the Caliph does not designate anyone.

The people of authority (Ahl al-Hall wal-Aqd) are representatives of the Ummah in choosing the Caliph. Their representation was implicit in the early days of Islam due to the Ummah's satisfaction with them. However, some scholars now believe it is necessary for them to be explicitly elected by the Ummah to represent it. This can be organized through local consultative councils (Shura councils) that progressively elect their representatives until the Commander of the Faithful (Amir al-Mu'minin) is chosen.

The flexibility of Islamic Sharia lies in the fact that beliefs (aqeedah) and acts of worship (ibadat) are definitive, while administrative and constitutional matters have been left to ijtihad (independent reasoning) and development, provided that the fundamental principles are maintained, such as the election of the ruler and his consultation with the people of authority (Ahl al-Hall wal-Aqd), while leaving the determination of the method and manner to the Ummah.