#572 Dirshu Mishna Berura Simon 242 seif 1 "To be careful with kavod Shabbos" (first Shiur of Hilchos Shabbos)
#575 Dirshu Mishna Berura Simon 243 seif 1 Rama sk 9 pg. 6 "Can you profit when a non-Jew does work on Shabbos?"