The word(s) "hard" appears 62 time(s) in 58 verse(s) in Quran in Muhammad Habib Shakir translation.

(1) And seek assistance through patience and prayer, and most surely it is a hard thing except for the humble ones,

(2) Then your hearts hardened after that, so that they were like rocks, rather worse in hardness; and surely there are some rocks from which streams burst forth, and surely there are some of them which split asunder so water issues out of them, and surely there are some of them which fall down for fear of Allah, and Allah is not at all heedless of what you do.

(3) And thus We have made you a medium (just) nation that you may be the bearers of witness to the people and (that) the Apostle may be a bearer of witness to you; and We did not make that which you would have to be the qiblah but that We might distinguish him who follows the Apostle from him who turns back upon his heels, and this was surely hard except for those whom Allah has guided aright; and Allah was not going to make your faith to be fruitless; most surely Allah is Affectionate, Merciful to the people.

(4) Surely those who believed and those who fled (their home) and strove hard in the way of Allah these hope for the mercy of Allah and Allah is Forgiving, Merciful.

(5) Do you think that you will enter the garden while Allah has not yet known those who strive hard from among you, and (He has not) known the patient.

(6) Thus it is due to mercy from Allah that you deal with them gently, and had you been rough, hard hearted, they would certainly have dispersed from around you; pardon them therefore and ask pardon for them, and take counsel with them in the affair; so when you have decided, then place your trust in Allah; surely Allah loves those who trust.

(7) The holders back from among the believers, not having any injury, and those who strive hard in Allah's way with their property and their persons are not equal; Allah has made the strivers with their property and their persons to excel the holders back a (high) degree, and to each (class) Allah has promised good; and Allah shall grant to the strivers above the holders back a mighty reward:

(8) But on account of their breaking their covenant We cursed them and made their hearts hard; they altered the words from their places and they neglected a portion of what they were reminded of; and you shall always discover treachery in them excepting a few of them; so pardon them and turn away; surely Allah loves those who do good (to others).

(9) O you who believe! be careful of (your duty to) Allah and seek means of nearness to Him and strive hard in His way that you may be successful.

(10) O you who believe! whoever from among you turns back from his religion, then Allah will bring a people, He shall love them and they shall love Him, lowly before the believers, mighty against the unbelievers, they shall strive hard in Allah's way and shall not fear the censure of any censurer; this is Allah's Face, He gives it to whom He pleases, and Allah is Ample-giving, Knowing.