"Excellent hands and occasional acquisitions" means: people with superb skills can obtain them accidentally. It is also used to describe people with profound literary literacy who can accidentally come up with witty works out of inspiration. From Song Luyou's "Articles".

Original poem:

The article was made by nature, but it was accidentally obtained by a good hand.

If it is completely flawless, why does it need artificial intervention?

Look at the ancient Yi utensils, they are ingenious and clumsy.

The Han Dynasty is the most recent pre-Qin Dynasty, and it is already extremely pure.

What is the Hu tribe doing? The bold bamboos are mixed with mourning threads.

If Hou Kui no longer writes, who will be responsible for the next millennium

Explanation:

The article is naturally made without artificial addition and is highly skilled. What people get by chance. Pure white has no flaws and does not require manpower to pursue it deliberately. Look at the ancient Yi vessels (bronze sacrificial vessels). They are delicate and clumsy and cannot be changed.

The Han Dynasty is the closest to the Pre-Qin Dynasty, but there is a big difference in the depth and shallowness of the articles. What is the music of the Hu people like? Just some orchestral instruments and silk and bamboo. Hou Kui (according to legend, he was Shun's music officer) no longer writes music. For thousands of years, who can compare with him?

Extended information::

In order to illustrate this truth, after raising the question, the author gave both positive and negative examples, and finally expressed the feeling that Hou Kui will never be seen again.

What the author calls "natural" does not refer to the gift of nature, but to the author's occasional inspiration based on his long-term accumulation of perceptual impressions and in-depth thinking.

As long as the article can be "pure and flawless" and "clever and clumsy", it is a good article. Liu Xizai, a native of the Qing Dynasty, said: "The advantage of Xijiang's famous masters is that they return to nature through exercise. Those who let Weng Ben learn from Xijiang said: 'The articles are made by nature, and a good hand can accidentally acquire them.' The achievements of the past training can be seen beyond words.

Baidu Encyclopedia - Article (Lu You’s Poems)