How is the definition of a single suckling (Rad'ah) determined?
General Chapter
Al-Mughni
Book of Fosterage (Breastfeeding)
Primary text
The standard for determining a suckling relies upon custom ('Urf) because the Lawgiver mentioned it absolutely without setting a time limit or quantity, indicating reliance upon custom. If the child suckles and then stops clearly by choice, that constitutes one suckling; returning to suckle constitutes another suckling.
Supporting text
If the child stops due to lack of breath, switching from one breast to another, distraction, or if the wet nurse interrupts, one must look further. If the child does not return soon, it is one suckling. If the child returns immediately, there are two views: one is that the first was a suckling, and the return constitutes another suckling (the choice of Abu Bakr and the apparent view of Ahmad). The second view is that all of it constitutes one single suckling (the madhhab of Ash-Shafi'i), except if the wet nurse interrupts, in which case there are two differing opinions concerning that exception.