What, then, constitutes a nursing that establishes prohibition? Is it a single suck, such that if the child sucks five times—even within a single breath—the prohibition is established? Or is one nursing when he takes hold of the breast, then releases it, breathes, and returns? Or is a nursing comparable to a meal—meaning that each nursing must be separate from the next, rather than occurring in one sitting?

The scholars have three views on this matter. The strongest is the last view, and it was the view preferred by our Shaykh, Abd al-Rahman ibn Saʿdi, may Allah have mercy on him. The reason is that we do not rule that a woman, for example, becomes unmarriageable except on the basis of evidence that admits of no alternative interpretation or other possible meanings. This last view admits of no other meaning, because it is the most stringent of the views stated. Accordingly, if a child nurses four times, taking five breaths during each nursing, the prohibition is not established according to the stronger view, unless each nursing is separate from the others.

Ibn al-Qayyim, may Allah have mercy on him, examined this issue closely in Zād al-Maʿād, and the student of knowledge should refer to it.

The second condition is that the nursing take place during the period in which the child is nourished by milk. Should this be determined according to what is generally the case, or according to the actual circumstances?

Here too, the scholars have two views:

The first view is that it is determined according to what is generally the case, namely two years. Thus, if nursing occurs after two years, it has no legal effect, whether the child has been weaned or not. Whatever occurs before the completion of two years establishes prohibition, whether the child has been weaned or not. This is the well-known position of the madhhab. They cite the saying of Allah Most High:

“Mothers may nurse their children for two complete years—for those who wish to complete the nursing period.” [Surah al-Baqarah: 233]