The speaker seems to be caught between the past and the evening coming on. The opening lines are odd and a little unsettling: an untruth "might fix me" if I keep walking with it. That could mean a comforting story about the past, one that holds the speaker in place or settles who they are. Then comes a calm, strange claim: "yesterday is road enough." The past is not something to escape but the ground the speaker walks on, and the line "I am full of time" suggests both richness and heaviness.
The "new stairs" lead down to "a rival," which hints at some tension or competing self, though the poem doesn't explain who that is. After that the scene softens into something ordinary: night approaching, supper being prepared. The final lines ask only to let night be itself, "first let me be." The mood is quiet, reflective and slightly wary, as if the speaker wants to stop sorting out memory and simply rest in the present for a while.