This chapter focuses on a new general subject relevant to all before blessings, and although relevant to the general rules of before blessings explained in chapter 7, due to its complexity and length we have dedicated a full chapter to the subject. The topic at hand is regarding the expiration of a before blessing and the requirement for it to be repeated. There are various reasons for why a before blessing that was said over food may need to be repeated, either over that same food or over a different food of that same blessing. One of these causes of repetition is due to Hesech Hadas, which is the removal of the mind of the person from the blessing that was said. Another reason and cause for needing to repeat a blessing is known as Hefsek which occurs upon switching locations [i.e. Shinuiy Makom]. The former aspect of Hesech Hadas will be explained in this chapter, while the latter aspect of Hefsek and Shinuiy Makom will be discussed in the next chapter, chapter 20. These chapters do not discuss the concept of Hefsek between the blessing and eating, nor do they discuss when a second food is considered included in the original blessing which was said on a first foods, as explained above in the note.

The concept of Hefsek versus Hesech Hadas:[3]

Throughout the laws of blessing repetition explained this and the next chapter, we find the terms Hesech Hadas and Hefsek used intermittently in the cases that require blessing repetition. In truth, it is a Hefsek within the eating which requires blessing repetition and not necessarily mere Hesech Hadas. Hence every Hesech Hadas that requires blessing repetition, in the scenarios to be explained, has reached the definition of a Hefsek and hence requires repetition. However, not every Hefsek is due to Hesech Hadas, such as in the scenario that one changed locations in which no Hesech Hadas has taken place, but it is nonetheless considered a Hefsek.[4] Likewise, not every Hesech Hadas is considered a Hefsek, and hence may not require repetition.