The word(s) "careful" appears 79 time(s) in 74 verse(s) in Quran in Muhammad Habib Shakir translation.

(61) O you who believe! avoid most of suspicion, for surely suspicion in some cases is a sin, and do not spy nor let some of you backbite others. Does one of you like to eat the flesh of his dead brother? But you abhor it; and be careful of (your duty to) Allah, surely Allah is Oft-returning (to mercy), Merciful.

(62) O you men! surely We have created you of a male and a female, and made you tribes and families that you may know each other; surely the most honorable of you with Allah is the one among you most careful (of his duty); surely Allah is Knowing, Aware.

(63) O you who believe! be careful of (your duty to) Allah and believe in His Apostle: He will give you two portions of His mercy, and make for you a light with which you will walk, and forgive you, and Allah is Forgiving, Merciful;

(64) O you who believe! when you confer together in private, do not give to each other counsel of sin and revolt and disobedience to the Apostle, and give to each other counsel of goodness and guarding (against evil); and be careful of (your duty to) Allah, to Whom you shall be gathered together.

(65) Whatever Allah has restored to His Apostle from the people of the towns, it is for Allah and for the Apostle, and for the near of kin and the orphans and the needy and the wayfarer, so that it may not be a thing taken by turns among the rich of you, and whatever the Apostle gives you, accept it, and from whatever he forbids you, keep back, and be careful of (your duty to) Allah; surely Allah is severe in retributing (evil):

(66) O you who believe! be careful of (your duty to) Allah, and let every soul consider what it has sent on for the morrow, and be careful of (your duty to) Allah; surely Allah is Aware of what you do.

(67) And if anything (out of the dowries) of your wives has passed away from you to the unbelievers, then your turn comes, give to those whose wives have gone away the like of what they have spent, and be careful of (your duty to) Allah in Whom you believe.

(68) Therefore be careful of (your duty to) Allah as much as you can, and hear and obey and spend, it is better for your souls; and whoever is saved from the greediness of his soul, these it is that are the successful.

(69) O Prophet! when you divorce women, divorce them for~ their prescribed time, and calculate the number of the days prescribed, and be careful of (your duty to) Allah, your Lord. Do not drive them out of their houses, nor should they themselves go forth, unless they commit an open indecency; and these are the limits of Allah, and whoever goes beyond the limits of Allah, he indeed does injustice to his own soul. You do not know that Allah may after that bring about reunion.

(70) So when they have reached their prescribed time, then retain them with kindness or separate them with kindness, and call to witness two men of justice from among you, and give upright testimony for Allah. With that is admonished he who believes in Allah and the latter day; and whoever is careful of (his duty to) Allah, He will make for him an outlet,