1. The Gemara explains that there are certain situations in which one should not pray.
2. When a person departs from his friend, he should teach a Halachah.
3. An intoxicated person may not say Shemoneh Esreh.
4. One may not sit within four Amos of a person who is reciting Shemoneh Esreh.
5. A non-Kohen may slaughter a Korban in the Beis ha'Mikdash.
A BIT MORE
1. For example, a person should not pray while he is upset, lazy, or in a lightheaded mood. It is best to pray after being gladdened by a Mitzvah.
2. One should not depart from his friend with lightheaded comments.
3. This is evident from the fact that Eli ha'Kohen thought that Chanah was drunk and, therefore, not allowed to pray.
4. This is evident from the fact that Chanah said that she was standing (not sitting) within Eli's area.
5. However, a non-Kohen may not receive or sprinkle the blood from the Korban.