Section

Allah Most High says:

“Say: He is Allah, One.”
“Allah, the Eternal Refuge.”

He prefixed the definite article al- to Samad (the Eternal Refuge), but not to ahad (One), because no existing being other than Allah Most High is called ahad in an affirmative statement when the word stands alone, without being joined to a following noun in a genitive construction. This differs from negative statements and constructions that function similarly, such as conditions and questions. Thus one says: “Is anyone with you?” and “If anyone comes to me from you, I will honour him.”

Otherwise, it is used only in simple counting: ahad, ithnān (one, two), and ahad ‘ashr (eleven). The first day is called yawm al-ahad (Sunday), for—according to the more correct of the two views—it was on that day that Allah began creating the heavens, the earth, and everything between them, as indicated by the Quran and authentic hadiths.

The Quran states in several places that He created the heavens, the earth, and everything between them in six days. It is established in an authentic hadith, whose authenticity is agreed upon, that Adam was the last creature to be created and that he was created on Friday. Since creation ended on Friday, it follows that it began on Sunday, because the days were six.

As for the hadith narrated by Muslim, which states:

“Allah created the soil on Saturday,”

it is a defective hadith whose authenticity was challenged by leading hadith scholars, including al-Bukhārī and others.