The speaker is waiting for someone to arrive, and the poem catches the moment when certainty starts to slip. It opens confidently: "you will come today." But the very next line, "tomorrow," corrects it. The arrival has been pushed back, perhaps not for the first time, and the speaker quietly adjusts without any complaint.
The final image does most of the work. Holding a wet finger to the wind is an old way of finding out which direction the breeze is coming from. Here, the speaker is doing the same thing with hope, trying to sense whether the person is on their way. It suggests they have no clear information, only a feeling they are trying to read.
The mood is patient but uneasy. There is longing here, and a kind of stubborn faith, yet the shortness of the lines and the sudden shift from "today" to "tomorrow" leave a little ache of doubt hanging in the air.