The refrain of Cheongsan-byeolgok, a Korean poem in the late Goryeo period, ‘얄리 얄리 얄라셩 얄라리 얄라’ might be the writing of five Mongolian sentences in the forms of the imperative of the second person and the voluntative of or with the verb yali-(‘to be in great quantity; to be of good quality’) and its subject še̱ng(‘a unit of measurement for volume’). The sentences demand or request something or someone for grains to be in great quantity(or to be of good quality), with the wish for a good harvest.
The four feet meter in the refrain may supplement the stability to the poem. And as a sort of terminal modification, it may reinforce the feeling of finality of each stanzas.
The sounds in the refrain serve the smooth, fluent, bright and refreshing feelings avoiding monotony. And the arrangement of the forms and sounds has some important functions and the effect of auditory harmony and so on.
Although they are irrelevant to the meaning and emotion of the poem in Korean, the sentences might have been entered into the position of refrain as a sort of praise to king at the performance of Cheongsan-byeolgok in the royal palace. And the refrain has played an impressive role as the words of adding to the fun.