As Long as one is Living Sustenance is Guaranteed
Imam Ibn Al-Qayyim
Concern yourself with that which you were ordered to take care of, and do not be concerned with something that was not guaranteed for you.
Sustenance and the matter of death are two matters whereof there is no doubt.
As long as one is living sustenance is guaranteed. And if Allah, according to His wisdom, closed the way to some means, He will, according to His mercy, open another means for you, which will be more useful. Let us consider the state of the embryo. It receives its nourishment, which is blood from one means which is the naval, and when it comes out of its motherýs womb and this only means is closed, another two means are opened to it, which are better and sweeter than the first!
The second means is pure and nourishing milk.
When he finished his suckling period and these two means are closed because of weaning, Allah opens four more perfect means; two kinds of foods and two kinds of drinks.
The two foods are from animals and plants and the two drinks are from water and milk, as well as whatever he likes from among other pleasures.
When he passes away, his four means are closed but Allah, the Exalted will open to him, if he was pious, eight doors of Paradise in order to enter Paradise from anyone of them, according to his wish.
So we notice that whenever Allah, the Exalted prevents His believing servant from something during this worldly life, He will bestow upon him something which is better and more useful to him. It should be noted that this is only granted to the believers. Allah preserves His servant from low and mean misfortunes and is not pleased when such fortunes comes to him, as He gives him a better and more valuable one.
The servant does not always recognize the generosity of Allah, His wisdom and kindness, nor does he always know the significant difference between what he was granted and what he was protected from. He is fond of matters being decided immediately even if they are mean, and refuses the latter ones even if they are better. If the servant could just treat Allah justly he would have known that the pleasures of this world that Allah has protected him from are better for him than those things which Allah may have granted him from these pleasures.
Allah prevented him from some of them in order to bestow upon him something that is better. He, the Almighty may have allowed him to be afflicted in order to protect him, tested to absolve him from sins, put him to death to resurrect him, and took him out of this world so as to stand in front of Him and follow the path that will bring him to Allah.
From Al-Fuwaid, A Collection of wise sayings, Ibn Al-Qayyim p.88
(from the English Translation of the book)