Qì Zhōng Zuò
Zǒumǎ xī lái yù dào tiān,
cí jiā jiàn yuè liǎng huí yuán.
Jīn yè wèi zhī hé chù sù,
píng shā mǎngmǎng jué rényān.
“碛(qì)” is the desert. It means the poem is written in the desert.
I gallop at full speed on a horseback from the west and come to this wide expanse of desert as if I arrive at the ends of the earth. I have seen the full moon twice since my departure from home (indicating he is away from home for two months). I have no idea where to camp tonight. I can hardly see any living beings in this vast and endless desert.
The poet Cen Seng has been to the west border twice and knew the life there very well. He was thus especially good at writing poems about the frontier. This poem is about the scene and military life he witnessed in the desert during the two months after leaving home. Though the scenery there was desolate, life was harsh and his longing for home was eager, the poet never felt sad and depressed but full of heroic passion.
一马平川（yì mǎ píng chuān）ph.a vast expanse of flat land
边塞（biānsài）n. frontier fortress
军旅（jūnlǚ）n. military related