Thirty
The triliteral root thā lām thā (ث ل ث) occurs in the Quran 32 times.
Thirty nights
(7:142) We appointed for Moses thirty (Arab. ثَلَاثِينَ, thalāthīna) nights and completed them with ten, so the appointed time of his Lord was completed at forty nights. Moses said to his brother Aaron: "Be my successor with my people and reform, and do not follow the path of the corrupters."
Thirty months
(46:15) We instructed the human being to honor his parents. His mother bore him with hardship, gave birth to him in hardship, and his weaning lasts thirty (Arab. ثَلَاثُونَ, thalāthūna) months. Until he has attained his maturity, and reaches forty years, he says: "My Lord, expand my abilities to be thankful for the blessings You have bestowed upon me and upon my parents, and to do righteousness that pleases You. Let my progeny be righteous. I have repented to You; I am of those who have peacefully surrendered."
See Also
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 19, 20, 30, 40, 50, 60, 70, 80, 99, 100, 200, 300, 1000, 2000, 3000, 5000, 50.000, 100.000.
