Part 4: "Divine Service"
Ch. 6: "The Sequence of the Day"
Paragraphs 16 & 17
Not only are there four metaphysical universes and four "prayer
universes" -- our prayers likewise affect the four parts of the day:
daytime (say, from 6 AM to 6 PM), evening (from 6 PM to 7:30 PM),
nighttime (from 7:30 PM to 4:30 AM), and daybreak (from 4:30 AM to 6 AM).
The prayers we'd discussed up to now have touched upon how we transmit G-
d's Providence in the course of the daytime, so let's now discuss prayer
in the other parts of the day (as well as a prayer service that's unique
to special days).
First off, it's important to point out that the morning service is the
longest, most complex one because we need to help transmit enough of G-d's
Providence then to last the entire day. The afternoon (Mincha) service is
accordingly fairly short, since only the evening has to be affected by it.
Now, since the difference between nighttime and daytime is greater than
the difference between daytime and evening, and since a lot of effort has
to be expended in order to transmit G-d's Providence in the course of the
night, the nighttime (Ma'ariv) service is longer than the afternoon one,
and it includes the vitally important Sh'ma Yisrael and its blessings
(though those blessings are much shorter than their morning version). The
nighttime Sh'mone Esrei was originally not obligatory, but it has become
our practice to recite it.
And though we'd expect there to be a prayer service between nighttime and
daybreak, no official service was instituted in fact, since it would be
too difficult for most of us to adhere to. There's in fact a midnight
service ("Tikkun Chatzot"), though, which centers on crying out to G-d to
restore the Holy Temple and to end the Exile that some devout souls engage
in, but it's not at all obligatory. It was instituted by King David (while
the other prayer services were instituted by Abraham, Isaac, and Jacob and
thus have greater weight).
Finally, we add an additional prayer service ("Mussaf") on Shabbat, The
New Month ("Rosh Chodesh"), and on every Yom Tov, since those days merit
an additional measure of Divine Providence (also see 4:6:12).