it may be a completion without which the matter remains valid, though it is sinful to omit it; and at other times, it may be a completion without which the matter remains valid and no sin is incurred. What is meant by completion in Urwah’s hadith, with respect to Muzdalifah, is the completion of an obligatory act that the worship remains valid without. This is the view of the majority.
Some scholars held that standing at Muzdalifah is a sunnah, not a pillar or an obligation, based on the Prophet’s statement: “Hajj is Arafah.”
However, the most balanced and soundest view is that it is obligatory, though not a pillar. One would be reluctant to tell someone who stood at Arafah, performed tawaf and sa'i, but did not stand at Muzdalifah, “You have no Hajj.” Rather, one should say to him: “Your Hajj is valid, but you must offer a sacrificial compensation,” as will be discussed under the obligations.
His statement, “Its obligations,” means: the obligations of Hajj. The difference between an obligation and a pillar is that Hajj remains valid without an obligation, whereas it is not valid without a pillar.
His statement, “Entering ihram from the miqat applicable to him”: this is the first of the obligations of Hajj—entering ihram from the miqat applicable to him. As for ihram itself, it is a pillar.
Had the author said, “That ihram be entered from the miqat,” it would have been clearer. For when he says, “Entering ihram from the miqat,” one might suppose that ihram from the miqat is also among the obligations, whereas it has already been explained that the miqats are five, and that whoever passes through one of them intending to perform the rites must enter ihram. Whoever is within their boundaries enters ihram from wherever he is, including the people of Mecca, who enter ihram from Mecca—except for Umrah, for which they enter ihram from the nearest point outside the Sacred Precinct. It has already been explained what the applicable miqat is; thus, the applicable miqat consists of the five miqats.