What is the meaning of the Hadith that forbids breathing into a vessel; and does this include private and public vessels, and does it prohibit blowing on tea to cool it?

The Prophet Muhammad (peace be upon him) forbade breathing into a vessel, because the breath may carry saliva, mucus, or an unpleasant odor, which could disgust the drinker or others. This prohibition includes both an individual drinking alone and someone sharing the drink with others, as it relates to cleanliness.

He also forbade blowing into a vessel, whether to cool food and drink or to remove impurities, because it often contains disgusting saliva. Furthermore, blowing on hot food may indicate haste, gluttony, and a lack of chivalry.

The prohibition against breathing and blowing into a vessel is a matter of detestability (karaha), not absolute prohibition (tahrim). It ceases to apply in cases of urgent necessity, such as when the food or drink is hot and waiting is difficult. However, it is preferable to avoid blowing even if it is hot, and it can be cooled by pouring it into another vessel.