Alone I have made the circuit of the vault of heaven: Alone is a way of saying that Wisdom is the only one ever to have done these things. I have made the circuit is literally “I circled,” that is, “I went around [it] in a circle.” The vault of heaven refers to the sky. In languages that have a specific word for “horizon,” for this line we may say “I alone have walked around the horizon.”

And have walked in the depths of the abyss: The depths of the abyss refers to the waters that the ancient Israelites believed lay beneath the earth; compare 1.3; Gen 7.11; 8.2; Pro 3.20. For this line Good News Translation is very clear with “and walked through the ocean beneath the earth.”

With this verse compare Pro 8.27-28.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on Sirach. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here.