Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(They) 'Abdullah Ibn Ubayy and his host (will swear by Allah unto you, when ye return) from the Battle of Tabuk (unto them) in Medina, (that ye may let them be) that you may pardon them and not punish them. (Let them be) and do not punish them, (for lo! they are unclean) impure and filthy, (and their abode) their destiny (is hell as the reward for what they used to earn) for what they used to say and do of evil.
They will swear to you by God, when you turn back, [when] you return, to them, from Tabūk, that they had [genuine] excuses for staying behind, so that you may leave them be, refraining from reproaching them. So leave them be, for they are an abomination, filth, on account of their inner vileness, and their abode shall be Hell, as requital for what they used to earn.
(In the end you will be brought back to the All-Knower of the unseen and the seen, then He (Allah) will inform you of what you used to do.) Allah will inform you of your deeds, whether they were good or evil, and will recompense you for them. Allah said that the hypocrites will swear to the believers in apology, so that the believers turn away from them without admonishing them. Therefore, Allah ordered disgracing them by turning away from them, for they are,
(Rijs) meaning, impure inwardly and in their creed. Their destination in the end will be Jahannam,
جَزَآءً بِمَا كَانُواْ يَكْسِبُونَ
(a recompense for that which they used to earn.) of sins and evil deeds. Allah said that if the believers forgive the hypocrites when they swear to them,
(certainly Allah is not pleased with the people who are Fasiqin.) who rebel against the obedience of Allah and His Messenger. `Fisq', means, `deviation'.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
The Arabic words and are of the same root but have different senses in the two sentences in which they occur. In the first sentence it means, "... so that you may turn away from them and forbear them and may not take them to task...." In the second sentence it means, "... so turn away from them and break off all connections with them and have nothing to do with them, as if you had broken off completely with them,, and they with you.''