and sent it down piecemeal, in separate portions, so that it could be memorized without needing a written copy, as Allah Most High says:

“Those who disbelieve say, ‘Why was the Quran not sent down to him all at once?’” And the rest of the verse.

Allah Most High also says:

“And a Quran which We have divided into portions.” And the rest of the verse.

“Do not hasten with the Quran.” And the rest of the verse.

“It is for Us to gather it and recite it.” And the rest of the verse.

In the Sahīh, Ibn ‘Abbās said:

“The Prophet, may Allah bless him and grant him peace, used to experience great difficulty when receiving revelation, and he would move his lips. Ibn ‘Abbās said, ‘I will move them for you as the Prophet, may Allah bless him and grant him peace, used to move them.’ He then moved his lips. So Allah Most High revealed: ‘Do not move your tongue with it to hasten it. It is for Us to gather it and recite it.’”

He explained: “To gather it in your heart, after which you will recite it.”

“So when We have recited it, follow its recitation.” He explained this as listening attentively and remaining silent.

“Then it is for Us to make it clear”—that is, “We shall make it clear through your tongue.”

Thus, whenever Gabriel came to the Prophet, may Allah bless him and grant him peace, he would listen. When Gabriel departed, the Prophet, may Allah bless him and grant him peace, would recite it as Gabriel had taught him.

For this reason, the Companions did not add dots or vowel marks to the written copies of the Quran. They were also Arabs who did not make errors in Arabic, so they had no need to specify the readings by adding dots. A single word could have two readings, one with yā’ and the other with tā’, such as ya‘malūna (“they do”) and ta‘malūna (“you do”). They therefore did not mark it for one reading in a way that would exclude the other.

Later, during the time of the Successors, when errors in Arabic began to appear, some of them began adding vowel marks and dots to the written copies of the Quran. They did this in red, indicating the a-vowel with a red dot above the letter, the i-vowel with a red dot below it, and the u-vowel with a red dot