Is it religiously appropriate to talk and express an opinion about Qadar (destiny)?

The Prophet Muhammad (pbuh) stated the following in a hadith:

“Do not talk about qadar because qadar is the secret of Allah. Do not attempt to explain the secret of Allah!”Alauddin Aliyyu'l Ibn Husamaddin al-Hindi, Kanzu'l Ummal, Vol. 1 p: 132

However, this hadith does not forbid us to try to understand qadar and it does not forbid us to try to understand the issue of qadar what is meant in the hadith is something different here.

Qadar is divided into two:

1-The first one is related to human free will.

2-The second one is related to the events that happen beyond a person's free will and control.

Being male or female, the time period that a person is born, the place he or she is born and lives, a person's lifetime, a person's mother and father, being disabled or healthy, being beautiful or ugly, being rich or poor can be mentioned as examples for the second part.

Trying to understand the secret of divine destiny in such cases, asking questions like, “Why did Allah do so? are a meaningless loss and can cause a person to go to Hell because, as a result of these questions, a person can rebel qadar, that is, divine destiny. These secrets will be understood in the hereafter with all details.

This is the part of qadar, the part which human will cannot intervene, that the Prophet Muhammad (pbuh) prohibits us from dealing with it by saying, “Do not talk about qadar, because it is the secret of Allah. Do not dare to explain the secret of Allah."   

Otherwise, thinking about the first part of qadar is good and it is regarded as meditative worshipping. Muslim scholars of creed have tried to understand this part of qadar and written books about it.