The Messenger of Allah (ﷺ) said to me: Keep fast for three days of month, and finish the recitation of the Qur'an in one month. I and he differed among ourselves on period of time. He said: Fast one day and give it up other day. The narrator 'Ata said: The people differed from my father (in narrating the period of time). Some narrated seven days and others five.
Sunan Abi Dawud Book 6, Hadith 19
← Previous Hadith The Prophet (ﷺ) as saying to him: Complete the recitation of the Qu'ran in one month. He said: I have more strength. He (the Prophet) said: Complete the recitation in twenty days. He again said: I have more energy. He said : Recite in fifteen days. He again said: I have more energy. He said: Recite in ten days. He again said: I have more energy. He said: Recite in seven days, do not add to it.

Abu Dawud said: The tradition narrated by Muslim is more perfect.

Sunan Abi Dawud Book 6, Hadith 18 Next Hadith → Yazid ibn Abdullah said that Abdullah ibn Amr asked the Prophet (ﷺ): In how many days should I complete the recitation of the whole Qur'an, Messenger of Allah?

He replied: In one month.

He said: I am more energetic to complete it in a period less than this. He kept on repeating these words and lessening the period until he said: Complete its recitation in seven days.

He again said: I am more energetic to complete it in a period less than this.

The Prophet (ﷺ) said: He who finishes the recitation of the Qur'an in less than three days does not understand it.

Sunan Abi Dawud Book 6, Hadith 20