It is a translation of a poem by Li Bai
The green mountains north of the suburbs lie,
White water 'round the East City flows by;
Here, once goodbye to each other we say,
For a thousand miles your lone boat will race.
The drifting clouds carry the wanderlust's feeling;
Our friendship is reflected by the Sun setting.
Waving hands, we go on our separate ways,
"Xiaoxiao, " sadly my dappled horse neighs and neighs.
https://www.poemhunter.com/poem/li-bai-the-green-mountains-north-of-the-suburbs-lie-white-water-round-the-east-city-flows-by/I'm told (by the clever one who speaks Chinese) there is a date/signature on the left but unable to make it out.
