The word(s) "careful" appears 3 time(s) in 2 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) When a (courteous) greeting is offered you, meet it with a greeting still more courteous, or (at least) of equal courtesy. Allah takes careful account of all things.

(2) O ye who believe! When ye go abroad in the cause of Allah, investigate carefully, and say not to any one who offers you a salutation: "Thou art none of a believer!" Coveting the perishable goods of this life: with Allah are profits and spoils abundant. Even thus were ye yourselves before, till Allah conferred on you His favours: Therefore carefully investigate. For Allah is well aware of all that ye do.