The word(s) "guarding" appears 4 time(s) in 4 verse(s) in Quran in Mohsin Khan translation.

(1) Allah! La ilaha illa Huwa (none has the right to be worshipped but He), Al-Hayyul-Qayyum (the Ever Living, the One Who sustains and protects all that exists). Neither slumber nor sleep overtakes Him. To Him belongs whatever is in the heavens and whatever is on the earth. Who is he that can intercede with Him except with His Permission? He knows what happens to them (His creatures) in this world, and what will happen to them in the Hereafter. And they will never compass anything of His Knowledge except that which He wills. His Kursi extends over the heavens and the earth, and He feels no fatigue in guarding and preserving them. And He is the Most High, the Most Great. [This Verse 2:255 is called Ayat-ul-Kursi ]

(2) He is the Irresistible, (Supreme) over His slaves, and He sends guardians (angels guarding and writing all of one's good and bad deeds) over you, until when death approaches one of you, Our Messengers (angel of death and his assistants) take his soul, and they never neglect their duty.

(3) And this (the Qur'an) is a blessed Book which We have sent down, confirming (the revelations) which came before it, so that you may warn the Mother of Towns (i.e. Makkah) and all those around it. Those who believe in the Hereafter believe in it (the Qur'an), and they are constant in guarding their Salat (prayers).

(4) There is no human being but has a protector over him (or her) (i.e. angels in charge of each human being guarding him, writing his good and bad deeds)