The word(s) "smooth" appears 3 time(s) in 3 verse(s) in Quran in Saheeh International translation.

(1) O you who have believed, do not invalidate your charities with reminders or injury as does one who spends his wealth [only] to be seen by the people and does not believe in Allah and the Last Day. His example is like that of a [large] smooth stone upon which is dust and is hit by a downpour that leaves it bare. They are unable [to keep] anything of what they have earned. And Allah does not guide the disbelieving people.

(2) It may be that my Lord will give me [something] better than your garden and will send upon it a calamity from the sky, and it will become a smooth, dusty ground,

(3) She was told, "Enter the palace." But when she saw it, she thought it was a body of water and uncovered her shins [to wade through]. He said, "Indeed, it is a palace [whose floor is] made smooth with glass." She said, "My Lord, indeed I have wronged myself, and I submit with Solomon to Allah, Lord of the worlds."