“ה’ אלקי אבותיכם אלקי אברהם אלקי יצחק ואלקי יעקב שלחני אליכם” (ג’,ט”ו)
The מכילתא (פרשת בא פרק ט”ז) says ומנין שאומרים ברוך אתה ה’ אלקינו ואלקי אבותינו, אלקי אברהם ואלקי יצחק ואלקי יעקב, שנאמר ויאמר עוד אלקים אל משה כה תאמר אל בני ישראל וגו’ – We learn from the above passuk the נוסח of the first brocha of שמונה עשרה.
The מחבר (סימן ק”א סעיף א’) rules that one must have kavanah by all of the brochos of שמונה עשרה. If one is not able to do so, he at least has to have kavanah by the brocha of avos. If not he must daven again. The רמ”א adds that today one does not repeat שמונה עשרה for lack of kavanah, for most likely he will also not have kavanah the second time around. Kavanah means the meaning of the words.
The Mishnah Berurah brings from the חיי אדם that since מדינא one really has to go back, therefore if he realized he did not have kavanah before he said ברוך אתה ה’ at the end of the brocha, he should go back to אלקי אברהם and say it over with kavanah.
The halacha is that if one only said the beginning and end of the brocha and not the middle he is יוצא בדיעבד. The נחלת אליהו has a ספק if this halacha also applies to the brocha of avos. Do we say that avos is included in this halacha or do we say that since the brocha of avos is different than the other brochos that מדינא one has to have kavanah even בדיעבד, therefore the middle can’t be left out even בדיעבד.
Reb Aharon Leib zt”l has a ספק if one just said ואלקי אבותינו without specifying each of the Avos. He brings a proof that one is still יוצא. Even if he only says וזוכר חסדי אבות which is only a רמז to the avos he is still יוצא. However the חפץ חייים has a צד to say the whole נוסח הברכה is לעיכובא. This is also the opinion of the Steipler zt”l.
The חזון איש holds that if one did not have the proper kavanah, as long as he did not yet start the next brocha he can have kavanah right now for the previous brocha. The Biur Halacha writes that one should wait until חזרת השץ and have kavanah for the first brocha and then continue. However this is not the מנהג העולם.[1]
Prepared by R’ Avrohom Yehoshua Ziskind
[1] Sources,אילת השחר,משנה ברורה,אשי ישראל