Such claims are mere sophistry—grievous unbelief, patent ignorance, obstinate rejection of what is plainly perceived, and a denial of the Lord of earth and heaven. All the adherents of the revealed religions who transmit from the Messengers of the Most Merciful, together with what has been handed down among people throughout every age, concur that the Flood did in fact occur, that it engulfed the whole earth, and that God left not a single unbeliever alive. In this He answered the supplication of His divinely aided, infallible Prophet and fulfilled what had already been decreed in the immutable divine decree.

***
A glimpse of Noah’s own qualities, peace be upon him

God the Exalted says:
“Indeed, he was a grateful servant.” (al-Isrāʾ 17:3)
It is said that he would praise God for his food, his drink, his clothing, and every aspect of his life.¹

Imām Aḥmad² narrated: Abū Usāmah related to us, Zakariyyā ibn Abī Zāʾidah related to us, from Saʿīd ibn Abī Burdah, from Anas ibn Mālik, who said that the Messenger of God ﷺ said:
“God is pleased with a servant who, when he eats a meal, praises Him for it, or when he drinks a draught, praises Him for it.”
Muslim, al-Tirmidhī, and al-Nasāʾī likewise transmitted it³ through the narration of Abū Usāmah.

The apparent meaning is that the truly thankful (al-Shakūr) is the one who performs every act of obedience—of heart, tongue, and limb—for gratitude is manifested by all three. As the poet said:

Your favors drew from me three things in return—
my hand, my tongue, and the guarded inner heart.⁴

***
His fasting, peace be upon him⁵

Ibn Mājah⁶—Chapter: The Fasting of Noah, peace be upon him—said:
“Sahl ibn Abī Sahl narrated to us; Saʿīd ibn …”