Boyd’s Bible Dictionary:

Concise Bible Dictionary:

Abihu and Nadab, sons of Aaron, with seventy of the elders of Israel, were invited to ascend with Moses, where they saw God and did eat and drink (Ex. 24:1,9-111And he said unto Moses, Come up unto the Lord, thou, and Aaron, Nadab, and Abihu, and seventy of the elders of Israel; and worship ye afar off. (Exodus 24:1)
9Then went up Moses, and Aaron, Nadab, and Abihu, and seventy of the elders of Israel: 10And they saw the God of Israel: and there was under his feet as it were a paved work of a sapphire stone, and as it were the body of heaven in his clearness. 11And upon the nobles of the children of Israel he laid not his hand: also they saw God, and did eat and drink. (Exodus 24:9‑11)
). They were consecrated to minister to the Lord as priests, yet on the first occasion of their exercising the priesthood for Israel they offered strange fire, which the Lord had not commanded, and were smitten by fire from God (Lev. 10:1-21And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the Lord, which he commanded them not. 2And there went out fire from the Lord, and devoured them, and they died before the Lord. (Leviticus 10:1‑2)). Immediately before this we read that “there came a fire out from before the Lord and consumed upon the altar the burnt offering and the fat.” That fire was never to go out, and doubtless the fire Abihu should have used was the fire that was upon the brazen altar, as is ordained in Leviticus 16:1212And he shall take a censer full of burning coals of fire from off the altar before the Lord, and his hands full of sweet incense beaten small, and bring it within the vail: (Leviticus 16:12). We read elsewhere that everything was to be done “as the Lord commanded Moses”; but of this which Nadab and Abihu did, it expressly says it was not commanded; therefore it was sin, and God was dishonored. Their death followed, and Aaron and his other sons were not to leave the tabernacle nor mourn for the dead (Num. 26:60-6160And unto Aaron was born Nadab, and Abihu, Eleazar, and Ithamar. 61And Nadab and Abihu died, when they offered strange fire before the Lord. (Numbers 26:60‑61); 1 Chron. 24:1-21Now these are the divisions of the sons of Aaron. The sons of Aaron; Nadab, and Abihu, Eleazar, and Ithamar. 2But Nadab and Abihu died before their father, and had no children: therefore Eleazar and Ithamar executed the priest's office. (1 Chronicles 24:1‑2)). The case of Nadab and Abihu should teach us that not every kind of worship is acceptable to God; “they that worship him must worship him in spirit and in truth” (John 4:2424God is a Spirit: and they that worship him must worship him in spirit and in truth. (John 4:24)); mere outward worship will not do and it must be according to what God has revealed. If separated from the sacrifice of Christ it is but the energy of nature, and is offensive to God.

Strong’s Dictionary of Hebrew Words:

from 1 and 1931; father (i.e. worshipper) of Him (i.e. God); Abihu, a son of Aaron
KJV Usage:

Jackson’s Dictionary of Scripture Proper Names:

my father is he, or "father of him"

Potts’ Bible Proper Names:

He is a father; father, i. e., worshiper, of Him, i. e., God:―son of Aaron, Exod. 6:23. {Ille est pater}