Partial Credit for Partial Counting

Starting with the second day of Pesach, the Torah (Vayikra 23,15-16) commands us to count 50 days in anticipation of Shavuos when we commemorate receiving the Torah at Har Sinai. The Sefer haChinuch (Mitzvah 306) explains that the idea behind this mitzvah is that exodus from Egypt and slavery were only significant if we were to become Am Yisroel by keeping Torah and Mitzvos. Counting each day as it goes by is how we express our recognition and excitement of the Torah as the true meaning of our freedom. 

Based on this, there is a dispute amongst the Rishonim if each day is an independent count, or because we are counting a unit of time from Pesach until Shavuos, it is one large count, and if one missed a single day, they can no longer count towards Shavuos. The Mechaber accounts for both opinions by ruling (O.C. 489,8) that one who missed a day should continue to count without a bracha. 

If someone is certain that they will be unable to count all 49 days of the Omer, the Nishmas Avraham wonders if they can start counting with a Bracha. Because in terms of the bracha, we rule like the opinion that it is one continuous count (because safeik brachos lechumra), should a person who knows they will not complete the mitzvah begin it with a bracha? R’ Shlomo Zalman Auerbach ruled that such a person should count with a bracha until they miss a day. Similarly, in Shu”t Shraga Hameir, Rabbi Shraga Schienobolg ruled this way because even if the mitzvah is to count all 49 days, we still consider each day to be its own mitzvah, as evidenced by the bracha made every day. 

However, according to the Ben Ish Chai, someone in this scenario should not begin counting with a beracha. This is because L’chatchila, one should not make a beracha on a partial mitzvah. Because our subject does not anticipate being able to count each day until Shavuos, he only intends to do part of the mitzvah, and thus does not make a beracha at all.