The word(s) "forty" appears 4 time(s) in 4 verse(s) in Quran in Saheeh International translation.

(1) And [recall] when We made an appointment with Moses for forty nights. Then you took [for worship] the calf after him, while you were wrongdoers.

(2) [Allah] said, "Then indeed, it is forbidden to them for forty years [in which] they will wander throughout the land. So do not grieve over the defiantly disobedient people."

(3) And We made an appointment with Moses for thirty nights and perfected them by [the addition of] ten; so the term of his Lord was completed as forty nights. And Moses said to his brother Aaron, "Take my place among my people, do right [by them], and do not follow the way of the corrupters."

(4) And We have enjoined upon man, to his parents, good treatment. His mother carried him with hardship and gave birth to him with hardship, and his gestation and weaning [period] is thirty months. [He grows] until, when he reaches maturity and reaches [the age of] forty years, he says, "My Lord, enable me to be grateful for Your favor which You have bestowed upon me and upon my parents and to work righteousness of which You will approve and make righteous for me my offspring. Indeed, I have repented to You, and indeed, I am of the Muslims."