Translation:

118. (He turned in mercy also) to the three who were left Behind: (they felt guilty) to such a degree that the earth seemed constrained to them for all its speciousness and their (very) souls seemed straitened to them and they perceived that there is no fleeing from Allah and no refuge but to Himself. Then He turned to them that they might repent: for Allah is Oft-Returning Most Merciful.

Notes (Tafseer)

1370. Left behind: i.e., the acceptance of their repentance was delayed. Among the Faithful, the largest number consisted of those who were perfectly staunch and ever ready to do their duty. They obtained the love and good pleasure of Allah. Next came a few who wavered because their will was weak and they were daunted by the dangers and difficulties that faced them; Allah's saving grace protected them and they conquered their weakness, and did not fail in their duty; Allah forgave them and accepted their repentance. Lastly, in the illustration taken from the Tabuk affair, there were some who actually failed in their duty, not from contumacy or ill-will, but from thoughtlessness, slackness, and human weakness: they actually failed to obey the Holy Prophet's summons, and were naturally called on to explain, and were excluded from the life of the Community. Their mental state is here described graphically. Though the earth is spacious, to them it was constrained. In their own souls they had a feeling of constraint. In worldly affluence they felt poor in spirit. They realised that they could not flee from Allah, but could only find solace and refuge in coming back to Him. They freely repented and showed it in their deeds, and Allah freely forgave them and took them to His grace. Though illustrated by the particular examples of Ka'b, Mararah and Hilal, the lesson is perfectly general and is good for all times.