原文：

康熙年间，有王生者，家贫而好学。常于夜读，灯下苦思。一日，忽闻窗外有声，如有人语。王生惊起，见一白衣人立于窗前，形貌清奇，飘然若仙。

白衣人曰：“君非王生乎？吾乃司文郎也，掌人间文章之权。君文章虽佳，然命途多舛，今有一事相告：君若能改过自新，勤勉学问，日后必有所成。”

王生闻言大喜，跪拜谢曰：“愿闻其详。”白衣人曰：“君之文章，虽工整华丽，然过于雕琢，失却自然之趣。今后当以朴实为本，方能登堂入室。”

言毕，白衣人化作清风而去。王生自此谨记白衣人之言，潜心读书，文章渐趋简练自然。数年后，果然高中举人，名震乡里。

翻译：

In the reign of Emperor Kangxi, there was a man named Wang who was poor but fond of learning. He often studied at night under the lamplight, pondering diligently. One evening, he suddenly heard a sound outside his window as if someone were speaking. Startled, Wang rose and saw a white-robed figure standing by the window, with an extraordinary appearance that seemed almost ethereal.

The robed figure said, "Are you not Mr. Wang? I am the Lord of Literary Works, responsible for the authority over human writings. Your essays are commendable, yet your life has been fraught with adversity. Today, I have something to tell you: If you can repent and work harder on your studies, success will surely come."

Hearing this, Wang was overjoyed and knelt to thank him, saying, "I wish to hear more details." The robed figure replied, "Your essays, though well-structured and elegant, are overly ornate, losing the natural charm. From now on, take simplicity as your foundation, and you will achieve great heights."

With these words, the robed figure vanished into thin air. Since then, Wang followed the advice earnestly, immersing himself in study. Over time, his writing became concise and natural. A few years later, he indeed passed the imperial examinations and became renowned throughout his hometown.

以上为《聊斋志异·司文郎》的原文及其翻译，希望对大家有所帮助。