Eleazar (Eleazer): Son of Aaron
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Exodus 6:23
And Aaron married Elisheba, the daughter of Amminadab and sister of Nahshon, and she bore him Nadab and Abihu, Eleazar and Ithamar.
Exodus 28:1
“Next, have your brother Aaron brought to you from among the Israelites, along with his sons Nadab, Abihu, Eleazar, and Ithamar, to serve Me as priests.