Know that the heart of a person of sound mind cannot be free of sadness, because they always remember their previous sins. If a heart is devoid of sadness, it will become desolate. Just as a house becomes desolate if no one resides in it.
This is the sadness of the righteous, sadness for their sins. It is different to excessive sadness that causes one to grieve for the things of this world. One should not dwell excessively on things that they do not have or have ‘missed’. When one focusses excessively on the things of this world, the fear of the Day of Judgement leaves their heart.
The best of cures for sadness is to know that one cannot bring back what one has missed, and that by feeling sad, you are only adding to your misfortune, making two misfortunes rather than one. If you can free your hearts from this type of attachment, you can free yourself from the sadness of the things of this world.
Ibn Umar, may Allah be pleased with him, said: “If Allah takes something away from you, get busy with anything that will make you not think about it.”
Remember that with every suffering comes ease. If we focus on the coming ease, it can help us get through the pain of the present. Whatever Allah gives you to replace what He has taken away, will be better. Allah knows what is best for us and we don’t. It may be that a thing that we love is not good for us, and a thing that we dislike has good in it that we cannot see. And Allah is Al-Alim, the All-Knowing, and Al-Hakim, the All-Wise.
Know that what calls to sorrow and sadness is Hawa, or the desires, and not the mind, simple because the mind does not call to that which is not useful. One of things that makes excessive sadness disappear is to believe in the greater reward for patience when facing a trial, and to remind yourself of those afflicted with worse misfortunes than yours.