'Over the vast desert a lone plume of smoke rises straight; on the long river the setting sun is round' are the most famous lines of On a Mission to the Frontier.
Tips
history
In 737 王维 was sent from the capital to the northwestern frontier to carry the emperor's congratulations to a general who had defeated the Tibetans, and wrote the poem on the way.
usage
使 here is 'to go as an envoy', 至 'to arrive' and 塞上 'the frontier lands', so the title reads 'sent as an envoy, arriving at the frontier'.