This is a very bleak part of the Hobbits' and Strider's journey to reach the safety of Rivendell. They have left the Marshes and are out in the open. There is fear both ahead and behind. Strider seems doubtful of what precisely lay ahead, and the fall weather has brought cold evenings and mornings. The Hobbits yearn for hearth and home, but manage to stay cheerful as is their nature.
It is just in these sorts of places that Tolkien will bring the haunting beauty of his poetry as an oasis in the gloom. Strider speaks of Gil-galad and Sam supplies the verse.