It happens quite commonly during the period of Sefirat Ha’omer that somebody asks his friend after sundown which number should be counted that evening, before the friend has himself counted the Omer. It might appear, at first glance, that if the friend responds, then he effectively fulfills the Misva, and then cannot count the Omer later with a Beracha. What is the proper way to respond to such an inquiry to avoid forfeiting the Beracha over this Misva?
Hacham Ovadia Yosef rules that in order to avoid all potential problems and complications, it is preferable to respond to the inquiry by informing the questioner of the previous night’s counting. For example, if somebody asks his friend after sundown on the fourteenth night of the Omer which day he should count (and the friend has not yet counted), it is best for the friend to respond, "Last night was the thirteenth day." This response avoids all potential Halachic complications, and the friend can, according to all authorities and without any doubts, later count the Omer properly with a Beracha.
Another option is to answer the question directly, stating that night’s counting, but with the clear, explicit intent not to fulfill the Misva of Sefirat Ha’omer with this response. If a person performs a Misva act with the specific intention not to fulfill the Misva, then he does not fulfill the Misva. Thus, for example, on Sukkot, when we must recite the Beracha over the Arba Minim (four species) before fulfilling the Misva, one may lift the Arba Minim with the specific intent not to fulfill the Misva, and then recite the Beracha. (Others first lift the Lulab without the Etrog, and then lift the Etrog only after reciting the Beracha.) Here, too, if a person specifically has in mind not to fulfill the Misva of Sefirat Ha’omer when he responds to his friend’s inquiry, "Today is such-and-such day of the Omer," then he does not fulfill the Misva, and he may thus count again later with a Beracha.
If a person did not employ either of these options, and instead answered the question directly without explicit intent not to fulfill the Misva, has he forfeited the Beracha, or may he still count with a Beracha despite having already stated the day of the Omer?
Hacham Ovadia rules that the Halacha depends on the particular situation. If this occurred during the first six days of the Omer, when the counting entails simply stating the number of days, as there are as yet no complete weeks to count, then one indeed forfeits the Beracha if he gives an explicit answer. Meaning, if a person informs his friend, "Tonight is the fifth night," then he may not count with a Beracha that night. Even though he counted in English, his counting is valid and he has fulfilled the Misva, and so he cannot count again with a Beracha. Needless to say, he resumes counting with a Beracha the next night.
If, however, he responded by simply stating the number – "Five" – without stating, "Tonight is the fifth night," then he may still count that night with a Beracha. Hacham Ovadia ruled that we may employ in this situation a "Sefek Sefeka," or "double doubt." First, it is possible that he has not fulfilled the Misva since he did not intend to fulfill the Misva through his response, and it is possible that the Misva cannot be fulfilled without the intention to do so ("Misvot Serichot Kavana"). And even if we accept the premise that Sefirat Ha’omer, as a Rabbinical obligation (as opposed to a Biblical obligation), does not require intent, it is possible that one cannot fulfill the Misva without explicitly stating, "Today is…" Hence, as there are two uncertainties concerning the status of the individual’s response, he is allowed to count again properly with a Beracha in this case.
Starting from the seventh day, and through the end of the Omer period, one may count with a Beracha even if he had explicitly informed his fellow of that night’s counting, such as if he explicitly stated, "Tonight is the fourteenth night." After the sixth day, this individual will always be in a situation of "Sefek Sefeka," since according to some authorities one does not fulfill the obligation of Sefirat Ha’omer after the sixth day if he counts only the days, without counting the weeks. And since, as mentioned, we may also take into account the possibility that the Misva is not fulfilled without intent, a person may count with a Beracha even if he had given a direct response to his friend’s inquiry. It must be emphasized that this applies only after the sixth night of the Omer, from the seventh night of the Omer until the end of the Omer period. (Of course, one certainly should not respond by stating both the days and the weeks; for example, one should not say, "Tonight is the fourteenth night, which is two weeks." If he does, then he may not then count with a Beracha that night.)
As mentioned, however, it is far preferable to respond to such an inquiry by mentioning the previous night’s counting. Besides avoiding all complications, it also makes it clear to the questioner that one should not respond directly to such a question before one has counted. If one answers directly, even in a permissible manner, as outlined above, the questioner, who is unfamiliar with these Halachic intricacies, might mistakenly assume that one may always respond directly to this question without it affecting his recitation of the Beracha later on. For this reason, too, it is best to respond indirectly, by mentioning the previous night’s counting.
Summary: If a person is asked after sundown which night of the Omer it is, and he has yet to count the Omer that night, he should respond by noting the previous night’s counting, rather than answering directly. This is the preferred method of answering such a question. Another, though less preferred, option is to answer directly with specific intent not to fulfill the Misva. If one answered the question directly, by stating "Today is such-and-such day," without the specific intent not to fulfill the Misva, he may nevertheless count that night with a Beracha. If, however, this occurred on one of the first six nights of the Omer, then he cannot count later with a Beracha, unless he had only stated the number, without saying, "Today is…"