Chandogya Upanishad
Prapathaka II, Khanda 1
Meditation on the whole of the Sâman is good, and people, when anything is good, say it is Sâman; when it is not good, it is not Sâman.
Thus they also say, he approached him with Sâman, i. e. becomingly; and he approached him without Sâman, i. e. unbecomingly.
And they also say, truly this is Sâman for us, i.e. it is good for us, when it is good; and truly that is not Sâman for us, i. e. it is not good for us, when it is not good.