An agency contract (aqd al-wakalah) that is binding on either party or both (wakalah mulzimah). While agency is essentially not binding because each party has the right to revoke the contract (aqd), it becomes binding in the following cases: 1) when it involves the rights of others, 2) when it is a paid agency/ remunerated agency (wakalah bil ajr), 3) when the subject matter of contract is a task/ job that cannot be discontinued or interrupted without negatively impacting either party or both, and 4) when either party or both undertakes/ undertake not to revoke the contract within a specific period of time.