What part of speech is “steps”?

The verb to hold fast here is rendered not as a finite verb in the original, but as a type of infinitive (an infinitive absolute). Grammatically, it can be understood as a finite verb.¹ But that does not clear up what part of speech steps is; it could be either the subject or the object. That is, the sentence could be rendered either as, My steps have held fast to your paths, or, I have held fast my steps to your path. In the end, it makes little difference; the psalmist’s conduct followed closely the Lord’s paths.