哈里发是穆斯林的总领袖，其职责是建立伊斯兰的沙里亚法规，并将伊斯兰的呼吁（da'wah）传播至全世界。因此，建立沙里亚与将呼吁传播至世界，是哈里发职位得以存在的两项目的；这两项皆属于哈里发职位的工作。除哈里发本人外，任何人都不得监督这两项工作，哈里发也不得另行任命他人代替自己监督这两项工作，因为正是在这两项事务上给予了效忠（bay'ah），而效忠契约是缔结于他本人之上的。所以他不得委派他人去执行那项缔结契约所针对的工作。这是因为，凡是缔结于某个人身上的契约，例如雇员、代理人和合伙人的契约，该人都不得委派他人去执行契约所涉及的工作。当哈里发契约缔结于某位特定的人身上时，此人不得委派他人代替自己，去承担哈里发契约所缔结于其身上的事务，即为穆斯林的总领导，以建立沙里亚法规并传播呼吁。

The Khalifah is the general leader of the Muslims in order to establish the Islamic Shar’a rules, and carry the Islamic da’wah to the world. So establishing the Shar’a and carrying the da’wah to the world are the two matters for the sake of which the post of the Khilafah exists; so both of them are the work of the post of the Khilafah. It is not correct for anyone to supervise them other than the Khalifah nor is it allowed for the Khalifah to establish someone who would supervise both of them instead of him because they are the two matters upon which the bay’ah is given and the bay’ah contract takes place upon his person. So he is not allowed to delegate someone else to perform the work upon which the contract took place. This is because each contract which occurred upon the contractor’s person like the employee, agent and partner it is not permitted for him to delegate someone else to perform the work over which the contract took place. When the Khilafah contract occurs upon a specific person, it is not allowed for this person to delegate someone else to stand in his place in what the Khilafah contract occurred upon his person, which is the general leadership of Muslims to establish the Shar’a rules and carry the da’wah.