This is a poem from Melchior Sylvester Eckhard's Epigrammata, published in 1629; you can read the book online.
Numquam vertigo sinit hunc consistere in alto,
Qui nondum didicit repere pressus humi.
The vocabulary is keyed to the DCC Latin Vocabulary list. There are two words in this poem that are not on the DCC list:
rēpō, rēpere: creep, crawl
vertīgo (vertīginis, f.): dizziness, vertigo
altus -a -um: high, lofty; deep
cōnsistō -sistere -stitī: take position; consist (+ abl.)
discō -ere didicī: learn
hic haec hoc: this; hōc: on this account
humus -ī f.: ground; humī: on the ground
in: in, on (+ abl.); into, onto (+ acc)
nōndum: not yet
premō premere pressī pressum: press, pursue, overwhelm
qui quae quod: who, which, what / quis quid: who? what? which?
sinō sinere sīvī situm: allow, let go