Psalms 51:4

Psalms 51:4. Against thee, thee only, have I sinned, and done this evil in thy sight: that thou mightest be justified when thou speakest, and be clear when thou judgest.

He had sinned against his people, setting them an ill-example - sinned against Bath-Sheba and Uriah; but he sees the whole evil concentrating itself, as it were, upon his God. He felt that the virus of the whole thing was that he had done dishonour to the name of the Most High, whose servant he was.