The word(s) "vast" appears 5 time(s) in 5 verse(s) in Quran in Saheeh International translation.

(1) So if they deny you, [O Muhammad], say, "Your Lord is the possessor of vast mercy; but His punishment cannot be repelled from the people who are criminals."

(2) Allah has already given you victory in many regions and [even] on the day of Hunayn, when your great number pleased you, but it did not avail you at all, and the earth was confining for you with its vastness; then you turned back, fleeing.

(3) And [He also forgave] the three who were left behind [and regretted their error] to the point that the earth closed in on them in spite of its vastness and their souls confined them and they were certain that there is no refuge from Allah except in Him. Then He turned to them so they could repent. Indeed, Allah is the Accepting of repentance, the Merciful.

(4) The heavens almost rupture therefrom and the earth splits open and the mountains collapse in devastation

(5) Those who avoid the major sins and immoralities, only [committing] slight ones. Indeed, your Lord is vast in forgiveness. He was most knowing of you when He produced you from the earth and when you were fetuses in the wombs of your mothers. So do not claim yourselves to be pure; He is most knowing of who fears Him.