The word(s) "hard" appears 65 time(s) in 56 verse(s) in Quran in Mohsin Khan translation.

(41) And that is not hard for Allah.

(42) Is he whose breast Allah has opened to Islam, so that he is in light from His Lord (as he who is a non-Muslim)? So woe to those whose hearts are hardened against remembrance of Allah! They are in plain error!

(43) And We have enjoined on man to be dutiful and kind to his parents. His mother bears him with hardship. And she brings him forth with hardship, and the bearing of him, and the weaning of him is thirty months, till when he attains full strength and reaches forty years, he says: "My Lord! Grant me the power and ability that I may be grateful for Your Favour which You have bestowed upon me and upon my parents, and that I may do righteous good deeds, such as please You, and make my offspring good. Truly, I have turned to You in repentance, and truly, I am one of the Muslims (submitting to Your Will)."

(44) And surely, We shall try you till We test those who strive hard (for the Cause of Allah) and As-Sabirun (the patient), and We shall test your facts (i.e. the one who is a liar, and the one who is truthful).

(45) Hastening towards the caller. The disbelievers will say: "This is a hard Day."

(46) Has not the time come for the hearts of those who believe (in the Oneness of Allah - Islamic Monotheism) to be affected by Allah's Reminder (this Qur'an), and that which has been revealed of the truth, lest they become as those who received the Scripture [the Taurat (Torah) and the Injeel (Gospel)] before (i.e. Jews and Christians), and the term was prolonged for them and so their hearts were hardened? And many of them were Fasiqun (the rebellious, the disobedient to Allah).

(47) That you believe in Allah and His Messenger (Muhammad صلى الله عليه وسلم) and that you strive hard and fight in the Cause of Allah with your wealth and your lives: that will be better for you, if you but know!

(48) Let the rich man spend according to his means; and the man whose resources are restricted, let him spend according to what Allah has given him. Allah puts no burden on any person beyond what He has given him. Allah will grant after hardship, ease.

(49) O Prophet (Muhammad صلى الله عليه وسلم)! Strive hard against the disbelievers and the hypocrites, and be severe against them; their abode will be Hell, and worst indeed is that destination.

(50) Verily, the rising by night (for Tahajjud prayer) is very hard and most potent and good for governing oneself, and most suitable for (understanding) the Word (of Allah).