Tafsir of Ash-Shu`ara' 26:80

This is a conjunctive clause following "He who feeds me and gives me drink," arranged alongside them in the string of attributes for a single relative pronoun. This is because health and illness are, for the most part, derivatives of eating and drinking, as ailments are most often seen to originate from food or drink. The wise have said: "If most of the dead were asked the cause of their appointed time, they would say: indigestion."

The attribution of illness—which is a hardship—to oneself, and the attribution of healing—which is a blessing—to Allah, the Glorified and Exalted, is done out of regard for proper etiquette. This is as Al-Khidr (peace be upon him) said: "So I intended to cause a defect in it," while he said afterward: "So your Lord intended that they reach maturity."

It does not contradict this that the act of causing death—which is more severe than illness—is attributed to Him, the Exalted and Majestic, in His saying: [The verse continues...].