Hilchos Shabbos siman shin pei vov seif ches part 2 10 minutes exploring the path Chovos Halevavos sha'ar yichud hama'aseh perek hey part 37, Sefer Mishna Brura, Chapter 5, Siman 386, Seif 8, Shulchan Aruch Orach Chaim

Rabbi Gabi Fried