Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates that the Noble Prophet (peace and blessings be upon him) forbade breathing into a vessel and blowing into it.

Ibn Mathna says: I was with Marwan when Sayyiduna Abu Sa'id (may Allah be pleased with him) arrived there. Marwan said to him: Have you heard that the Messenger of Allah (peace and blessings be upon him) forbade breathing into the drinking vessel? He said: Yes. And a man had said: O Messenger of Allah! I am not satisfied with the water drunk in one breath. The Messenger of Allah (peace and blessings be upon him) said to him: Then move the cup away from your mouth and breathe (and then drink again). He said: What if I see a straw in it? The Prophet (peace and blessings be upon him) said: Then pour it out.

Sayyiduna Abu Qatadah (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: When any of you drinks water, he should not breathe into the vessel; when he enters the toilet, he should not clean himself with his right hand; and when he urinates, he should not touch his private part with his right hand.