This article from Chabad.org discusses the halachic (legal) and Kabbalistic (mystical) explanations for ‘scratching’ the Challah before the blessing over the bread on Shabbat. Scratching, or placing a small cut in the top of the challah, is done immediately before the recitation of the blessing over the bread. This article is particularly helpful for those seeking a deeper understanding of the details of the ritual. Rabbi Aron Moss, a frequent contributor to Chabad.org. is the rabbi of the Nefesh Synagogue in Sydney, Australia.