Seven things are hidden from man. No man knows:

1. the day of [his] death;
2. the day of [Israel's] comforting;
3. the ultimate truth in divine judgments;
4. what is in his neighbor's heart;
5. what he will earn;
6. when the sovereignty of the house of David will return; or
7. when the kingdom of Edom will collapse.

Source: BT Pesahim 54b
English: The Book of Legends (Sefer ha-Aggadah):
Legends from the Talmud and Midrash
ed. H.Y. Bialik and Y.H. Ravnitzky
( Schocken Books, NY, 1992)