Man in black gives RIchard the dagger, wants him to kill 'the devil' (Jacob)

The man in black gives Richard some roasted boar which he quickly gobbles up. He tells Richard that once he's done eating, he should head west and once he reaches the ocean, he'll be able to see the statue that broke into pieces when the Black Rock smashed through it. He says that is where he'll find the devil (Jacob).

The man in black hands Richard a dagger which appears to be the same one Dogen gave Sayid. He then tells him to kill Jacob before he has a chance to speak because he's very persuasive. These are essentially the same instructions Dogen gave Sayid about killing Locke (the man in black).

The man in black tells Richard that he is the black smoke, but that Jacob took Isabella and he couldn't stop him. He tells him that Jacob took his body and his humanity and rebuts all of Richard's objections by asking him if he ever wants to see Isabella again. Richard takes the dagger and the man in black leaves.

So most of what the man in black says seems like lies to get people to do what he wants and that certainly seems to be the case here. He brings up Isabella over and over again. Much like when Ben lied though, I'd imagine there are bits of truth sprinkled throughout the lies.