The repetition of a certain Ayah adds to the beauty and eloquence of the authentic Word of God. It touches the hearts and minds of the believers. This repetition may be thought of as part of the style of the Word of God.
Unless repetition is useless and would not bring new meanings, it would not be recommended to be used. The Quran does not use this kind of repetition.
Repetition is a factor in speech accuracy, and it is under the
Al-Etnab category which is a language tool that deals with direct and indirect repetition, the indirect one such as saying the sentence then explaining it.
Repetition has many functions, such as making the meaning stronger, making the sentence longer, showing the importance of the issue and direct the intention, that can be seen in Al-Rahman chapter when God says:
Then which of the favors of your Lord will ye deny?
This sentence was repeated 31 times, because each time God mention his favors, so he want to direct the intention toward it's importance.
The Quran uses repetition, as the accuracy of the speech requires showing a meaning in many different forms, and the repeated stories need to be introduced differently every time its mentioned so the reader does not get bored but rather than that he would find new meanings form the other repetitions.
Some of the ways Quran uses repetition is through showing the summarized version of the story then exploring it, sometimes it mentions the end and the purpose of the story then starts exploring it. It has the feature of the good use of the story through ignoring the unimportant parts, leaving the brain thinking about it while mentioning the important events.
One of the repetition functions is to break down the ideas of one story in a way that makes the overall meaning stronger with the addition of new words.
Two of the aims of the Quran are to direct people intention toward God and educate people, these two points need special care, as it not enough to mention them only for once, but it needs continuous reminding, as God said:
Remind people as reminding is beneficial to the believers. And it is quite wise to remind people to do good.
The language scholar Salah Abd Al-Tawab says: The importance of repetition was in reminding people and in increasing the effect of what was reminded. It is not easy for any one to understand the importance of repetition. The Quran uses it very well that it looks perfect.
Repetition is repeating the story with the same words and the same meaning and this can not be of any use. But if it was repeated in different way with different words and situation it is not considered repetition, but rather it is considered completiion and as a type of variation.
The language scholar Mohammed Qutb said: In fact it is not repetition but it is a matter of variation. You can't find two exactly same sentences in the Quran, though you can find similarities, as the relation between relatives, they are not repeated. Variation is also used to avoid making the reader bored.
Religion scholar Abdull Rahaman Al-Maidani said: For any one who thinks there is a word by word repetition in the Quran, he should find the wisdom behind this repetition and he should find the differences in the meanings for the repeated sentences even it had minor differences.
It can be thought that there is repetition for some subjects, but in reality there is no repetition, it is actually completing each other to deliver the overall meaning.
As examples for repetition and variation, the stories in the Quran are introduced differently each time, it is repeated to deliver the special purpose that the God want to deliver. Every time the story is repeated you would find differences in its words and parts and there is so much need to change the words positions and to mention stuff would be ignored in other situations, as require for the accuracy of the speech.
Said Qutb said in his famous book "Fe Dhelal Al-Quran" –the favor of the Quran-: The stories in the Quran come in different positions for different situations, and these situations determine the story properties. When ever the story is repeated it has different functions.
The language scholar Fadhel Al-Samorai said: It would seem that the story is being repeated, but in fact in each time it would bring new ideas, as it required for the overall meaning.
The religion scholar Muhammed Al-Butti said: It could happen that some stories are repeated as that is required to deliver the educational message held by the story. Each time the story comes in different ways and you would feel as you read it for the first time.
In Al-Butti explanations, he brought examples that happened in Moses story –Peace Be Upon Him- story, that had many functions and teaching purposes. So when God wanted to make Mohammed –Peace Be Upon Him- and his friends feel strong, he would mention Moses's victory over pharaohs and his army. And when people think that they are the best, the Quran would mention what happened between Pharaohs and Moses –Peace Be Upon Him- including the conversations. And there are more to learn from Moses story.
In conclusion, In spite of the differences in the ideas around the Quran uses of repetition, they all agree that every situation requires different treatment and every situation would bring a new meaning directly or indirectly through concluding it.
http://www.nakcollection.com/video-l...ran-quran-gems
http://www.usislam.org/11law.htm
http://www.ebnmaryam.com/vb/t18805.html
https://islamqa.info/en/82856