Once he said, ‘let us bentch’ he is forbidden to drink - כיון דאמר הב וניבריך איתסר למישתי
Summary:
We maintain that to combine for (leading a) bentching one must eat together with the others (and eat a כזית of grain), however ר"ש בן שטח seemingly disagrees with this.
Rav Ashee recited a blessing over the first cup, but afterwards he no longer recited a blessing - רב אשי בריך אכסא קמא ותו לא בריך
Summary:
Whenever a מצוה requires a כוס of wine, no בפה"ג is required if there was no הפסק (from a previous בפה"ג). The הגדה and הלל are considered a הפסק requiring a בפה"ג on 'כוס ב' וד. A ברכה אחרונה should be said after כרפס, and the four כוסות (except for 'כוס ב) and also after ברכות אירוסין ונשואין.
Summary:
According to פי' הקונטרס the דיוק is since they did not institute בפה"ג twice, and according to תוספות the דיוק is since they did not institute it לבסוף.
Summary;
We always recite the בפה"ג on כוס ברהמ"ז. No additional ten זהובים need to be paid for forgoing leading the bentching, since there is the view of ר"א, and it is not always done.
