This poem comes from the Silva distichorum moralium by François Oudin (1719).
Pauca diuque, puer, meditata loquare; loquenti
Quod semel exciderit, non revocare licet.
The vocabulary is keyed to the DCC Latin Vocabulary list. There are two words in this poem that are not on the DCC list:
excidō, excidere, excidī: fall out, escape
meditātus, -a, -um: considered, pondered
diū: for a long time
licet licuit licitum est: it is permitted (+ dat. of person + infin.); conj. licet: even though
loquor loquī locūtus sum: speak, talk
paucī -ae -a: few
puer puerī m.: boy; slave
que (enclitic) - and
qui quae quod: who, which, what / quis quid: who? what? which?
revocō -āre: call back, recall