Members of a group were reclining to drink (and eat) and left that location to greet a groom or a bride.
According to the Talmud, meals are bracketed by blessings. There is a blessing said just prior to eating and drinking (known as a berakha rishona — a “before” blessing) and another said upon completion (what is known as a berakha aharona — an “after” blessing). In this scenario, a group of people had sat down and recited the first blessing to begin their meal. But sometime before the completion of the meal, a groom or bride passed nearby, and the assembled diners rushed out to greet them. The Gemara wants to know: Do they need to recite a berakha aharona before they run off? And when they return, do they then need to recite another berakha rishona to resume eating and drinking?
Initially, the Gemara rules that this is not necessary:
When they exit, we do not require a blessing to be recited afterward, and when they return they do not require an introductory blessing.
When these diners temporarily leave their location to greet a newlywed, they are not considered as having fully left the meal and so they neither need to recite a blessing to conclude their snack, nor a further blessing upon resuming.
However, the Gemara next qualifies this rule by limiting its application to a more specific case:
In what case is this statement said? When they left an elderly or a sick person. However, if they did not leave an elderly or sick person when they exit, the food that they have already eaten requires a concluding blessing; when they return, the food that they will eat requires an introductory blessing.
A group cannot be viewed as maintaining a presence in a location without, well, maintaining some presence in that location. In this case, that function is filled by an elderly or sick person who is unable to run out and join the celebratory cheer of the rest of the group. In this way, though they miss the excitement, the infirm person serves a significant purpose in “holding down the fort.”
Truth be told, I don’t know too many people who regularly dine with elderly and sick companions and then spring from their seats to greet newlyweds. But if I did, I suspect that aside from whatever words they mutter before or after their meals, such people are living a life of blessing.