The Laws of Prayer /The Blessings of the Shema (64)

1. After the first verse of the Shema, one says the verse “Baruch sheim…”, as this is what Yaakov said to his children after they said the verse “Shema…”. However, since this verse is not written in the Pentateuch, it is said quietly, so that it is clear to all that it is not part of the paragraph. (Shulchan Aruch and Mishne Berurah 61)

2. If one recited the Shema and forgot to recite the verse of Baruch Sheim, one has fulfilled one’s obligation and is not obligated to repeat it. (Shulchan Aruch and Mishne Berurah 61)