Nicene and Post-Nicene Fathers, Ser. II, Vol. VI:
The Letters of St. Jerome.: Letter XXVIII

Letter XXVIII. To Marcella.

An explanation of the Hebrew word Selah. This word, rendered by the LXX. διάψαλμα and by Aquila ἀεί, was as much a crux in Jerome’s day as it is in ours. “Some,” he writes, “make it a ‘change of metre,’ others ‘a pause for breath,’ others ‘the beginning of a new subject.’ According to yet others it has something to do with rhythm or marks a burst of instrumental music.” Jerome himself inclines to follow Aquila and Origen, who make the word mean “forever,” and suggests that it betokens completion, like the “explicit” or “feliciter” in contemporary Latin mss. Written at Rome a.d. 384.