Shulchan Aruch: Chapter 650 - Required Measure of Myrtle and Willow Twigs

SECTION 650 The Required Measure of the Myrtle and Willow Twigs. (1–2)

1 The minimum length that is required for the myrtle and willow twigs is three handbreadths,1 i.e., 12 thumbbreadths.2 The shidrah (the spine)3 of the lulav may not be shorter than four handbreadths, so that the spine will extend [at least] a handbreadth above the myrtle and willow twigs, enabling [the lulav] to be shaken, for what is shaken is this handbreadth that extends beyond the bound set.4 (The three species together are called “the bound set.”5) This handbreadth must be part of the actual spine, without including the long leaves that continue upward beyond the spine.

Some authorities maintain that [it is sufficient that] these handbreadths be small, three-and-a-third thumbreadths each.6 Thus [the length of the myrtle and willow twigs] need not be more than ten thumbbreadths, and [the minimum length of] the lulav, thirteen-and-a-third thumbbreadths. This view may be relied upon in a pressing situation. Similarly after the event, if one already recited the blessing on a bound set [of the three species] that is only of the above length, he has discharged his obligation, and is not required to recite a blessing again. He should, however, take in hand valid [twigs of the desired length, though] without reciting a blessing.7

2 There is no upper limit to the length [of the myrtle and willow twigs]. One may add beyond their minimum length as much as he desires, provided that the spine of the lulav continues upward [at least] a handbreadth beyond the bound set [of the three species], to enable [the lulav] to be shaken.8