Eliezer asks:
Why do we need a Kal v'Chomer from Sotah to learn it's Mutar to use the Shem Hash-m?
Why isn't it Mutar because of Pikuach Nefesh?
Eliezer , Isreal
The Kollel replies:
Sholom Rav,
The Aruch la'Ner asks your Kashya. He answers based on the Gemara in Sanhedrin (Daf 74b) that wherever there is Chilul Hash-m, the consideration of Piku'ach Nefesh is pushed aside. David ha'Melech was concerned that erasing the Name of Hash-m involves Chilul Hash-m, so he looked for another Heter.
In Succah (53b) he gives a more complex answer.
Wishing you a Kesivah va'Chasimah Tovah,
Eliezer Chrysler