The Book of Purification - Sahih Muslim 279a

"When a dog licks a utensil belonging to any one of you, (the thing contained in it) should be thrown away and then (the utensil) should be washed seven times."

Scholarly Commentary

This hadith establishes the ruling regarding purification when a dog's saliva contaminates a vessel. The scholars have derived several important legal principles from this narration.

First, the command to discard the contents indicates the severity of the impurity. The dog's saliva is considered najis al-ayn (inherently impure), requiring complete removal of the contaminated substance.

Second, the seven washings demonstrate the thorough purification required. The majority of scholars hold that one of these washings must be with soil or earth, based on companion narrations, as earth possesses unique cleansing properties for this specific impurity.

Third, this ruling applies specifically to dogs, distinguishing them from other animals. The wisdom behind this strict treatment relates to both spiritual purity and physical hygiene, as modern science confirms dogs carry harmful microorganisms in their saliva.

The obligation remains whether the dog licks the inside or outside of the vessel, and applies to both food and drink containers. This ruling reflects the comprehensive nature of Islamic purification laws.