Eleazar was a common name among priests during this period. The fact that he was not killed in his care-taking duties suggests that he was a Levite. Reference to Abinadab will be made again in 2 Samuel 6:3, when the ark is moved to Jerusalem. He is said to have two other sons, Ahio and Uzzah. Most likely they were his grandsons, given the time that had passed since the ark first came to Kiriath-jearim.1
1 Les gens de Kirjath-Jearim vinrent, et firent monter l'arche de l'Eternel; ils la conduisirent dans la maison d'Abinadab, sur la colline, et ils consacrèrent son fils Eléazar pour garder l'arche de l'Eternel.