When his conception of GD matures further, and he understands the purpose for which he was created and brought into this fleeting world and recognizes the high degree of the next world, which is a lasting one, he will despise this world and its means and will commit himself in thought soul and body -to GD may He be exalted. pg 469
Daily Halacha: 23 Teves
During Birchos Kerias Shema and Shema- It is strictly forbidden to talk as it would be considered an interruption in the middle of a blessing, which may invalidate the blessing.
Between Ga'al Yisrael and Shemoneh Esreh- It is strictly forbidden to talk since it would interrupt the all-important connection between Geulah and Tefillah.
During Shemoneh Esreh - It is strictly forbidden to talk as it constitutes an interruption in davening If one spoke inadvertently during one of the blessings of Shemoneh Esreh, he must repeat the blessing.
After Shemoneh Esreh- It is forbidden to talk if it will disturb the concentration of others who are still davening.
During Chazaras ha- Shatz- It is strictly forbidden to talk since one must pay full attention so that he can answer. Amen properly. One who talks during chazaras ha-shatz is called "a sinner whose sin is too great to be forgiven." The poskim report that several shuls were destroyed on account of this sin.