The Rishonim disagree whether or not Mitzvot require intention. For instance, if one takes a Lulav and its species on the Sukkot holiday but did not intend to fulfill the Mitzvah by doing so, has he nevertheless fulfilled his obligation or not? This would indeed be subject to the above disagreement among the Poskim, for according to the opinion that Mitzvot do not require intention, this individual has, in fact, fulfilled his obligation. However, according to the opinion that Mitzvot require intention, this individual has not fulfilled his obligation, for he had no intention to do so.
Another example of this is one who eats Matzah on the first night of Pesach not in order to fulfill the Mitzvah, rather, in order to satisfy his hunger, according to the opinions that Mitzvot do not require intention, one has fulfilled the Mitzvah of eating Matzah on the first night of Pesach, for ultimately, one has fulfilled the commandment of Hashem by eating the Matzah. According to the opinion that Mitzvot require intention, however, one is obligated to eat Matzah again, for a lack of intention to fulfill the Mitzvah hinders fulfillment of the Mitzvah and it is as if one has not performed the action of the Mitzvah at all. The Poskim discuss this matter lengthily.
Maran Ha’Shulchan Aruch (Chapter 60, Section 4) rules that Mitzvot indeed require intention. Maran Rabbeinu Ovadia Yosef zt”l subsequently rules likewise, regarding both Torah and rabbinic Mitzvot. Thus, if one performed a Mitzvah without intending to fulfill one’s obligation, such as, if one picks up a Lulav in order to move it as opposed to with the intention of fulfilling the Mitzvah, one must perform the Mitzvah again. (Nevertheless, when doing so, one should not recite another blessing, for we follow the rule that “When in doubt regarding a blessing, do not bless”; thus, since there are opinions that maintain that one has already fulfilled his obligation even without specific intention, one should not recite another blessing.)
Based on this, one reciting Keri’at Shema must have specific intention to fulfill the Torah commandment of doing so before beginning one’s recitation. If one has not done so, one has not fulfilled his obligation.
Besides for this matter, one must likewise understand the meaning of each of the words of the first verse of Keri’at Shema; without this condition being fulfilled as well, one has not fulfilled his obligation of reciting Keri’at Shema and one must repeat it. In the next Halacha, we shall, G-d-willing, discuss the proper thoughts and intentions during the first verse of Keri’at Shema.
It is customary to cover one’s eyes with one’s right hand while reciting the first verse of Keri’at Shema. The primary reason for doing so is in order to focus one’s full concentration on the matter at hand and not to interrupt this by looking around at things that may impede one’s concentration.
