What are the literary devices used in Macbeth's dagger speech?

We can find Macbeth's famous dagger speech in Act 2 Scene I. Macbeth starts out his speech by referencing a dagger, which he sees in the confused recesses of his tortured mind. He addresses this dagger as if it were a person. We call this literary device apostrophe.

Macbeth's soliloquy typifies the conversation of a man in a heightened, psychotic state; his perceptions vacillate between reality and fantasy. Those in the late stages of psychosis often exhibit erratic patterns of speech, as does Macbeth in his soliloquy. After stating that the dagger is so real he can almost reach out and grab it, he proceeds to question whether the dagger is just a figment of his grand imagination.  He thinks he sees the dagger calling him to the place he originally intended to go, to do the things he originally intended to do. In his delusion of paranoia, he eventually decides that the dagger is sending him secret messages that only he can understand. After all, he sees 'gouts of blood' on the handle and blade that weren't there before.

Another example of apostrophe in the speech comes later when Macbeth addresses the 'sure and firm-set earth,' telling the ground not to advertise his path towards Duncan. He wants the earth to assist him in his mission by not divulging his whereabouts, in case his desired purpose is thwarted.

There are two allusions in this speech; Macbeth talks about 'Pale Hecate's offerings' and 'Tarquin's ravishing strides.' Allusions are brief and indirect references to things, people, or ideas with cultural, political, or historical significance. Hecate is a Greek goddess often associated with the underworld, ghosts, witches, and magic. The reference to 'withered murder' (here, murder is personified as a man ready to do his foul deed) moving quietly like Tarquin leads us to ponder the rape of Lucretia. As Tarquin's rape of Lucretia cost him his kingdom, so does Macbeth's eventual murder of Duncan. A fitting reference!

These allusions are part of the imagery (or mental images) utilized by Shakespeare to show us the state of Macbeth's mind as he contemplates murdering Duncan. The imagery encompasses ghosts, witches, imaginary daggers, and general evil under the cover of night, instilling dread in the reader.