This poem is from a book published in 1624 by Jean Pignewart (Iohannes Pignevvart), a Cistercian monk and scholar. He attributes his collection of distich poetry to "Cato Bernardinus," invoking both the legendary "Cato" of Latin distich fame and also Saint Bernard of Clairveax who was famously associated with the Cistercian order.
Lux et Nox
Luces et noctes orbis tenet ipse vicissim;
Non nisi lux caelo, non nisi nox erebo.
The vocabulary is keyed to the DCC Latin Vocabulary list. There are only two words in this poem not on the DCC list:
erebus (erebī, m.): god of darkness, the underworld
vicissim: in turn
caelum -ī n.: sky, heavens
et: and
ipse ipsa ipsum: him- her- itself
lūx lūcis f.: light of day
nisi/nī: if not, unless
nōn: not
nox noctis f.: night
orbis -is m.: circle; orbis terrārum: world
teneō -ēre -uī tentum: hold
