The word(s) "hard" appears 36 time(s) in 35 verse(s) in Quran in Muhammad Pickthal translation.

(11) And Moses said: Our Lord! Lo! Thou hast given Pharaoh and his chiefs splendour and riches in the life of the world, Our Lord! that they may lead men astray from Thy way. Our Lord! Destroy their riches and harden their hearts so that they believe not till they see the painful doom.

(12) Then after that will come seven hard years which will devour all that ye have prepared for them, save a little of that which ye have stored.

(13) Which he sippeth but can hardly swallow, and death cometh unto him from every side while yet he cannot die, and before him is a harsh doom.

(14) A similitude of those who disbelieve in their Lord: Their works are as ashes which the wind bloweth hard upon a stormy day. They have no control of aught that they have earned. That is the extreme failure.

(15) And Allah hath given you, of that which He hath created, shelter from the sun; and hath given you places of refuge in the mountains, and hath given you coats to ward off the heat from you, and coats (of armour) to save you from your own foolhardiness. Thus doth He perfect His favour unto you, in order that ye may surrender (unto Him).

(16) And they indeed strove hard to beguile thee (Muhammad) away from that wherewith We have inspired thee, that thou shouldst invent other than it against Us; and then would they have accepted thee as a friend.

(17) (Moses) said: Be not wroth with me that I forgot, and be not hard upon me for my fault.

(18) That He may make that which the devil proposeth a temptation for those in whose hearts is a disease, and those whose hearts are hardened - Lo! the evil-doers are in open schism -

(19) And strive for Allah with the endeavour which is His right. He hath chosen you and hath not laid upon you in religion any hardship; the faith of your father Abraham (is yours). He hath named you Muslims of old time and in this (Scripture), that the messenger may be a witness against you, and that ye may be witnesses against mankind. So establish worship, pay the poor-due, and hold fast to Allah. He is your Protecting friend. A blessed Patron and a blessed Helper!

(20) The Sovereignty on that day will be the True (Sovereignty) belonging to the Beneficent One, and it will be a hard day for disbelievers.