As-Salaam alaikum,

It was once said to Sayyadi Abu Bakr Siddiq, the first Caliph, may Allah be pleased with him, (during an illness), "Shall we call a physician for you"? to which he replied, "He has already seen me." It was then said to him, "What did He say to you"? He replied, ....."Verily, I do as I please."

And Usman, may Allah be pleased with him, asked Abdullah Ibn Mas'ud in his sickness, "what is your complaint?" He replied, "the Mercy of Allah". It was then said to him, "Shall we not call a physician for you"? to which he replied, "the physician is the one who made me sick."

This is explained in the light of ayat 119 of Surat Ma'eda of the Holy Qur'an: "Allah is pleased with them and they are pleased with Him". (5:119) Thus when we are contented, satisfied with Allah Ta'ala, we relinquish all choices and should anticipate Decrees of Allah with joy... especially noting that He is the Arranger of all affairs. One must never respond to Allah's bitter Decrees with either stoic indifference or dejectedness and despair.

We must realize that the choice of Allah, Most High Lord of the Universe, is better than our choice for ourselves, since there are consequences for events which we do not anticipate in our shortsightedness.

For further reading on this, see
Sayyadi Muhasibi's 'Book of Resolution and the Return to Allah.'