This rhyming distich comes from the Florilegium Gottingense edited by Voigt. This little saying about non per cornua taurum is a bit like our saying "money doesn't grow on trees" - in this case, good things aren't just dangling from the bull's horns for you to grab.
Ipse laborato! Non dicas "dat deus aurum;"
Dat deus omne bonum, sed non per cornua taurum.
The vocabulary is keyed to the DCC Latin Vocabulary list. There is only one word in this poem that is not on the DCC list:
taurus, taurī m. - bull
aurum -ī n.: gold
bonus -a -um: good
cornu -ūs n.: horn
deus -ī m.; dea -ae f. god; goddess
dīco dīcere dīxī dictum: say; causam dicere, plead a case; diem dicere, appoint a day
do dare dedī datum: give
ipse, ipsa, ipsum: him- her- itself
labōro -āre: toil, work; be in trouble
omnis -e: all, every, as a whole
per: through (+acc.)