This has been repeated twice so as to reassure the Holy Prophet that the bad times hp was passing through at that time would not last forever, but were going to be replaced by good times in the near future. On the surface this appears to be a contradiction that hardship should be accompanied by ease, for these two things do not co-exist. But the words "hardship with ease" instead of "ease after hardship" have been used in the sense that the period of ease is so close to it as if it were a concomitant of it.
Hardship is never absolute, for ease always accompanies it. When your burden became too heavy, We lifted up your heart and relieved you. The repetition suggests that the Prophet had endured serious hardship and much affliction. This reminder recalls the various aspects of care and concern shown to the Prophet and then reassures him emphatically. A matter which afflicts Muhammad’s soul so much must be very serious indeed. Then follows a statement pointing out the aspects of comfort and the factors contributing to the lifting up of hearts and spirits, which is of great help to Muslims as they travel along their hard and long way.
Yusuf Ali Explanation:
This verse is repeated for extra emphasis. Whatever difficulties or troubles are encountered by men, Allah always provides a solution, a way out, a relief, a way to lead to ease and happiness, if we only follow His Path and show our Faith by patience and well-doing. The solution or relief does not merely come after the Difficulty: it is provided with it. I understand the definite article in al-'usr in a generic sense, and translate: "every difficulty". In xcii. 7, I have translated Yusr as Bliss, and in xcii. 10 'Usr as Misery.
Javed Ahmad Ghamidi Explanation:
(Therefore, [rest assured,] with this difficulty) Ie., so close is this ease to the difficult time he is facing that it is almost adjacent.
([you are now facing], a great ease awaits.) The ease referred to in the verse is that which was afforded to the Prophet (sws) in Madīnah after migration. As a result, not only did his preaching endeavours lead to political authority, but also with this authority the whole of Arab became subservient to him.
(With this difficulty, a great ease awaits) The repetition emphasizes the glad tidings. The period in which this sūrah was revealed was apparently a very testing one. The Almighty presented various incidents of the Prophet’s life to assure him. He was told that the God Who endowed him with all these blessings was there to help him; very soon, these difficult times would give way to ease; the hindrances in his way would be removed and he and his companions would finally reach the destination the Almighty had appointed as an established practice for His messengers. The words are rather precise here. But in Sūrah al-Naṣr, details are cited. It is stated that God’s help and victory would come and the Prophet (sws) would see people entering the folds of Islam in multitudes.
So, my dear sisters and brothers in Islam, we must remember and should have firm faith that hardship is never absolute, for ease always accompanies it. Difficulties do go away and pave the way for ease provided one has faith in Allah and does not lose heart in the face of times, no matter how adverse and challenging. Floods wash away lands and houses, yet men rebuild what has been lost and continue living another life. In fact, losing heart and being scared of difficult times is something that Satan injects into us to break our will to carry one. So let us not have someone break our will and turn us into a failure. There is always light at the end of the tunnel that suddenly scares away the darkness we have been travelling in.