"Obstacles are long" comes from The Book of Songs, which means that the road ahead is full of obstacles and long. "The line will arrive soon" comes from Xun Zi's Self-cultivation, which means that as long as you keep going, you will definitely reach your destination. The original text of "the road is blocked and long" is "go back and follow it, and the road is blocked and long." The original text of "the line will arrive soon" is "although the road is near, it is impossible."
The Book of Songs is the earliest anthology of poems in China, with 35 poems (and 6 sheng poems with no words). It was called "Poetry" or "Poetry 3" in Zhou Dynasty and was written in the Eastern Zhou Dynasty. The source of poetry in The Book of Songs comes partly from collected folk poems and partly from poems presented by ministers. Xunzi's Self-cultivation is one of the Confucian classics of Xunzi's works.