7

  Thank you

The Sages taught: Seven matters are concealed from people, and they are:

1. The day of death; 
2. and the day of consolation from one’s concerns;
3. the profundity of justice, ascertaining the truth in certain disputes;
4. and a person also does not know what is in the heart of another; 
5. and a person does not know in what way he will earn a profit;
6. and one does not know when the monarchy of the house of David will be restored to Israel;
7. and when the wicked monarchy (which destroyed the Second Beit HaMikdash) will cease to exist.

Source: Pesachim, 54B.