This verse is part of a larger list of David's mighty men, specifically those who were warriors known for their bravery and skill. Let's break it down:

"Sibbecai the Hushathite":
Sibbecai is the name of a warrior.
"the Hushathite" means he was from the town or region of Hushah. This was a way of identifying people, especially since many might have shared the same name. It's similar to using a last name or a town of origin today.

"Ilai the Ahohite":
Ilai is another warrior's name.
"the Ahohite" indicates he was from the region or clan of Ahoh. Again, it serves as a way to distinguish him.

In summary, the verse simply names two of David's mighty warriors and their place of origin or tribal affiliation. It provides information about their identities and connects them to specific places. The implication is that they were recognized and respected warriors within David's army, likely contributing significantly to his military successes.