"And when We bestow favor upon man," meaning: the polytheist, i.e., We grant him safety and well-being, "he turns away" from Allah and His worship, "and stands aloof," distancing himself from Allah, feeling independent of Him. "And when evil touches him," meaning illnesses and adversities, "he is ever despairing," meaning: he despairs that it will be relieved from him, because he lacks true intention and seeking of reward (hisbah).
﴿وَإِذا أنعمنا على الْإِنْسَان﴾ يَعْنِي: الْمُشْرِكَ؛ أَيْ: أَعْطَيْنَاهُ السَّلَامَةَ والعافية ﴿أعرض﴾ عَنِ اللَّهِ وَعَنْ عِبَادَتِهِ ﴿وَنَأَى بجانبه﴾ تَبَاعَدَ عَنِ اللَّهِ مُسْتَغْنِيًا عَنْهُ ﴿وَإِذا مَسّه الشَّرّ﴾ الْأَمْرَاض والشدائد ﴿كَانَ يئوسا﴾ أَيْ: يَئِسَ أَنْ يُفَرَّجُ ذَلِكَ عَنْهُ، لِأَنَّهُ لَيْسَتْ لَهُ نِيَّةٌ وَلَا حسبَة.