Positive commandment · Mitzvat Aseh #169 of 613
To take the lulav [and the other three species on Sukkot]
ליטול לולב
The verse · Vayikra 23:40
וּלְקַחְתֶּם לָכֶם בַּיּוֹם הָרִאשׁוֹן פְּרִי עֵץ הָדָר כַּפֹּת תְּמָרִים וַעֲנַף עֵץ־עָבֹת וְעַרְבֵי־נָחַל וּשְׂמַחְתֶּם לִפְנֵי ה׳ אֱלֹהֵיכֶם שִׁבְעַת יָמִים
“And you shall take for yourselves on the first day the fruit of the tree hadar, branches of palm trees, and the boughs of thick leaved trees, and willows of the brook; and you shall rejoice before the Lord your God seven days.”
The Rambam’s words
To take the lulav [and the other three species on Sukkot], as [Leviticus 23:40] states: "And you shall take for yourselves on the first day, the fruit of a beautiful tree, a palm branch,...."
ליטול לולב, שנאמר: "ולקחתם לכם ביום הראשון, פרי עץ הדר כפות תמרים" (ויקרא כג,מ).
Why · Sefer HaChinuch #324
Taking the lulav
“From the roots of the commandment, [there is a need to] preface [that] I have already written to you several times in what preceded, my son — that a man is impacted according to his actions that he constantly does; and his thoughts and pursuits are all caught according to the deeds of his hands, whether good or bad.”
Who & when
“And this commandment is practiced in every place and at all times by males, but not by females.”
Where in the Mishneh Torah
Hilchot Shofar, Sukkah and Lulav הלכות שופר וסוכה ולולב