What is sempai saying before mokuso?

Everytime we sit in seiza before the practise start, highest rank sempai first on the line says something before mokuso, it starts with shi... but I never understand what is he saying. Can you tell me?

Answer: Thank you for your question. Since those commands can be different from dojo to dojo, I can only guess.

Shisei wo Tadashite

Does it sound like that?