"We will surely cause him to live a good life." The interpretation of Wahb ibn Munabbih: It means contentment.
﴿فلنحيينه حَيَاة طيبَة﴾ تَفْسِيرُ وَهْبِ بْنِ مُنَبِّهٍ: يَعْنِي: القناعة.