السلام
كلمة (السلام) في اللغة مصدر من الفعل (سَلِمَ يَسْلَمُ) وهي...
The time between the disappearance of the red twilight until the end of the first third of the night.
“‘Atamah” (darkness) is the time for the “‘ishā” prayer. The Bedouins named the “‘ishā” prayer the “‘atamah” prayer because of its delayed timing. This is why it is prohibited to call this prayer the “‘atamah” prayer, to honor using the Shariah approved words. In some Prophetic narrations, however, the “‘ishā” prayer was called the “‘atamah” prayer. Nevertheless, it is best to adhere to the words used in the Qur’an, and if the opposite happened, then it should not be the popular usage.
“‘Atamah”: pitch darkness. It is the darkness that one sees once the light from the twilight disappears. It is derived from “ta‘teem”, which means to delay. The night prayer (“‘ishā” prayer) was named the “‘atamah” prayer because its time is delayed. Other meanings: concealing, covering.