[If] a good deed happens to you," meaning: victory, "it distresses them," that good deed.
"And if a disaster befalls you," meaning: a catastrophe from the polytheists, "they say, 'We had taken our matter [in hand] before,'" meaning: we have taken precautions by opposing Muhammad and staying away from him. "And they turn away," to their homes, "exultant," over the catastrophe that has afflicted the Prophet (peace and blessings of Allah be upon him) and the believers.
﴿إِن تصبك حسنةٌ﴾ يَعْنِي: النَّصْر ﴿تسؤهم﴾ تِلْكَ الْحَسَنَةُ.
﴿وَإِنْ تُصِبْكَ مُصِيبَةٌ﴾ أَيْ: نَكْبَةٌ مِنَ الْمُشْرِكِينَ ﴿يَقُولُوا قَدْ أَخَذْنَا أَمْرَنَا مِنْ قَبْلُ﴾ أَيْ: أَخَذْنَا الْوَثِيقَةَ فِي مُخَالَفَةِ مُحَمَّد، وَالْجُلُوس عَنهُ ﴿ويتولوا﴾ إِلَى مَنَازِلهمْ ﴿وهم فَرِحُونَ﴾ بِالَّذِي دَخَلَ عَلَى النَّبِيِّ ﷺ وَالْمُؤْمِنِينَ مِنَ النكبة.
