“May God preserve the supreme leader and give him a long life,” said Hojat al-Islam Ghorbanali Dorri-Najafabadi. “However, we need to prepare for when he is gone.”

These comments, which were picked up by Shia Online, went largely unnoticed when they were made May 20. However, this is one of the most candid comments made by a member of the Assembly of Experts about their constitutional role of both choosing the next supreme leader and supervising him after Ayatollah Ali Khamenei's reign ends. The topic came up while he was talking to reporters about the importance of the next Assembly of Experts election in February 2016.

By physical appearances, the 75-year-old Ayatollah Khamenei appears healthy. Iranian TV often shows him hiking in the mountains. He is capable of delivering long sermons and does not appear to be suffering from any mental fatigue or age-related illness. But the issue of succession is still very important for political groups in Iran.

Once the Assembly of Experts hold their election, the winners will hold the position for eight years. When that term comes to an end, the supreme leader will be 83 years old. Therefore, the possibility exists that the next elected Assembly of Experts might have to choose, or at the very least plan, a successor for Ayatollah Khamenei.