And the three upon whom the decision was left behind, for them the earth seemed to be constrained despite its vastness and their soul confined them and they were certain that there is no refuge from Lord Allah except into Him; then He turned to them so they could repent; Indeed, Allah is the Oft-Returning, the Merciful.
After returning to Medina from Tabuk Expedition, the hypocrites approached Messenger for explaining excuses for not participating with him. Messenger didn’t take any action in their case. But three persons named Ka’b-Ibnu-Malik, Hilal-Ibnu-Ummayyath, and Mararh-Ibnu-Rubbay had full faith in Islam and were also desirous of participating in the battle. But as they had not followed Messenger, they thought that they could join with him later. But Satan obstructed them from going. So, these three didn’t have any excuse to tell the Messenger. So, Messenger postponed deciding their case until Lord’s Decision comes. And he ordered them not to mingle with the believers. Then after 40 days, Messenger ordered them to stay away from their wives, and thus their soul felt difficulties as mentioned in this verse. At last, they repented sincerely to Lord and after 50 days, by accepting their repentance Lord revealed this verse. As a ransom, they gave their property which made them stay behind into the cause of Lord.
Lord is harsh upon those who do offenses knowingly. It is told about Messenger in verses 17: 74-75: “And if We had not strengthened you, you would have almost inclined to them a little. Then, We would have made you taste double punishment in this life and after death; then you would not find any helper against Us”. It is told about wives of Messenger in verse 33: 30: “Whoever from you commits clear immorality, she has the punishment in double, and it is very easy for Lord”.
When Lord commanded Messenger Moses to approach Pharaoh mildly with the Guidance as told in verses 20: 43-44, instead of accepting Lord, Pharaoh denied It and he proclaimed to the people that he is the lord, highest as told in verse 79: 24. When Pharaoh denied the Truth even after giving much time for realizing, the Three-Time-Knower Lord commanded Moses to pray as explained in verse 10: 88. Thus Lord seized him by drowning him along with his folk in the sea and secured his body as a sign for mankind until the Last Day as explained in verses 10: 90-92.
Even though the Battle of Uhud which happened in Hijra 3rd year was to separate the hypocrites from the believers, Messenger was commanded to deal gently with the hypocrites as explained in verse 3: 159. But after Tabuk Expedition, Lord commanded Messenger to deal harshly upon the believers who didn’t follow with him. Lord commanded Messenger not to pray for the hypocrites as explained in verses 9: 84-85. Moreover, He also commanded to do great Jihad against the Kuffar and hypocrites as explained in verse 9: 73. The command of verses 4: 91; 9: 5, 123 and 33: 60-61 which says that the hypocrites and Mushriks should be killed will only be implemented by the second coming of Jesus. See explanations 2: 272; 7: 150 and 9: 28.