Does prohibition result from the milk being administered via 'Sa'ut' (pouring into the nose) or 'Wajur' (pouring into the throat)?
General Chapter
Al-Mughni
Book of Fosterage (Breastfeeding)
Primary text
The sounder of the two narrations holds that prohibition is established through 'Sa'ut' and 'Wajur', just as it is established through regular suckling. This is the position of Ash-Sha'bi, Ath-Thawri, the Ashab ar-Ra'y, and Malik concerning 'Wajur'. The evidence is the hadith narrated by Ibn Mas'ud from the Prophet, peace be upon him: "There is no suckling except that which strengthens the bone and grows the flesh," reported by Abu Dawud. Because this method delivers the milk to where it reaches via suckling and achieves the growing of flesh and strengthening of bone, it must equate to suckling in establishing prohibition, just as the nose is a pathway for breaking the fast, it is a pathway for prohibition like the mouth.
Supporting text
The second narration states that prohibition is not established through these methods. This is the choice of Abu Bakr, the madhhab of Dawud, and the opinion of 'Ata' al-Khorasani concerning 'Sa'ut'. The argument is that this is not actual suckling, and the Lawgiver only prohibited by suckling, and since it occurs without actual suckling, it is analogous to something entering a wound on the body.