in Sharia, two units; therefore, it is necessary to apply the vow to it. As for the Witr, it is a voluntary prayer, and the vow is mandatory, so applying it to the obligatory is more appropriate. Furthermore, a single unit does not suffice in an obligatory prayer, so it does not suffice in a vow (4), just like a prostration. Al-Shafi'i has two opinions, just like the two narrations. As for if one specifies a number in his vow, it is binding upon him, whether it is small or large; because the vow is established by his statement, and thus is its number. If he intends a number, it is as if he had named it, because he intended with his wording what it could encompass, so its ruling becomes binding upon him, like an oath.

1856 - Issue; He said: (And if one vows to walk to the Sacred House of God, it does not suffice him unless he walks during a Hajj or Umrah, and if he is unable to walk, he shall ride and perform the expiation for an oath.)

The summary of this is that whoever vows to walk to the Sacred House of God, fulfilling his vow is binding upon him. Malik, al-Awza'i, al-Shafi'i, Abu 'Ubayd, and Ibn al-Mundhir held this view. We do not know of any disagreement regarding this; this is because the Prophet, peace and blessings of God be upon him, said: "Journeys are not to be undertaken except to three mosques: the Sacred Mosque, this mosque of mine, and the Al-Aqsa Mosque" (1). Walking does not suffice him unless it is during a Hajj or Umrah. Al-Shafi'i says this as well. I do not know of any disagreement regarding it; this is because the walking that is known in Sharia is the walking during a Hajj or Umrah. Therefore, when the one making the vow speaks generally, it is understood according to what is known in Sharia, and walking is binding upon him for it, due to his vow to walk (2). If he is unable to walk, he shall ride and is subject to the expiation for an oath. There is another narration from Ahmad that a sacrifice (dam) is binding upon him. This is the opinion of al-Shafi'i (3). 'Ata' issued a legal ruling (fatwa) for this, based on what Ibn Abbas narrated: that the sister of 'Uqbah ibn 'Amir vowed to walk to the Sacred House of God, and the Prophet, peace and blessings of God be upon him, commanded her to ride and to offer a sacrifice (hady). It was narrated by Abu Dawud (4), and it contains a weakness. Also, because she failed to perform something mandatory in the state of Ihram, a sacrifice became binding upon her, like one who leaves out the Ihram from the Miqat. It was narrated from Ibn 'Umar and Ibn al-Zubayr that they said: "She shall perform Hajj the following year, and she shall ride what she walked and walk what she rode" (5). Ibn Abbas said something similar (5), and added: "And she shall offer a sacrifice." From al-Hasan are the same opinions.