“My companion laid hands on a friend.

He violated a covenant with me.

His speech was smoother than butter.

But war was in his heart.

His words were softer than oil.

But in fact they were drawn swords.”

Now David picks on one person, his friend and companion.  He had violated an agreement with David.  His speech and words were smoother than butter and softer than oil.  What a metaphor!  Butter and oil, things we like, were used to show the sweet talking friend.  However, war was in his heart.  His words were like drawn swords.