What is the method for distinguishing between the pillars of Hajj and its obligations?

The questioner: Our Shaykh, the question is as follows: How do we distinguish between the pillars of Hajj and its obligations?

The Shaykh : This question cannot be answered in brief; rather, the evidence must be considered, and the evidence differs from one ritual to another. For example, what is the evidence that standing at 'Arafah is a pillar? His saying (peace and blessings be upon him): What is the evidence that the Fajr prayer at Muzdalifah is a pillar? The answer is that the relationship to this differs from that, and it is that the Prophet (peace and blessings be upon him) linked the Fajr prayer at Muzdalifah with standing at 'Arafah, and in addition to this linking, he said: Whoever stands For example, the Tawaf al-Ifadah differs entirely in its evidence for being a pillar. As far as I know, it is the consensus of the scholars regarding its consideration as a pillar, and perhaps I will say this, and perhaps among their evidence for it—and it is a precise observation—is that when the Prophet (peace and blessings be upon him) intended to return to Madinah and announced that to his Companions, some of his household said: Safiyyah has started menstruating. He said (may Allah's prayer and peace be upon him): They said: O Messenger of Allah, she has performed Tawaf al-Ifadah. He said: So first, he (peace and blessings be upon him) gave a general command for the Farewell Tawaf, and his saying (peace and blessings be upon him), after he understood or was informed that Safiyyah had performed Tawaf al-Ifadah, that she was permitted to depart, indicates that this hadith shows the Prophet (peace and blessings be upon him) distinguished between Tawaf al-Ifadah and the Farewell Tawaf. If the Farewell Tawaf is obligatory, what is Tawaf al-Ifadah? It should be a pillar. So there is no general rule by which we can understand the pillars of the Hajj rituals through a specific observation; rather, each of the Hajj rituals must be studied on its own. This is the answer I have. Yes.