Numbers 1:12

Modern

…from Dan, Ahiezer son of Ammishaddai;

Traditional

Of Dan; Ahiezer the son of Ammishaddai.

Literal

From Dan, Ahiezer son of Ammishaddai.

Latin

…de Dan, Ahiezer filius Ammisaddai;

Hebrew

English

…from Dan, Ahiezer son of Ammishaddai;

those who are twenty years of age or older by their divisions—everyone who can serve in Israel’s army: This registration gathered more information than the earlier census (compare Exodus 38:26).
These are the names of the men who are to assist you: Hebrew culture was tribal, centered around clans and families. They easily identified the tribal leaders, who appear again as a group in Numbers 7.
Moses and Aaron did not include the tribe of Levi in this registration because it had a special status in Israelite society (see Numbers 1:47–53; 26:51–62; Deuteronomy 18:5; 33:8–11).

God chose a family leader from each tribe (except the tribe of Levi), to count Israel's men who were old enough to be soldiers.

Numbers 7:66
On the tenth day Ahiezer son of Ammishaddai, the leader of the Danites, drew near.
Numbers 2:25
On the north side, the divisions of Dan are to camp under their standard: The leader of the Danites is Ahiezer son of Ammishaddai,
Numbers 10:25
Finally, the divisions of the camp of Dan set out under their standard, serving as the rear guard for all units, with Ahiezer son of Ammishaddai in command.

Ahiezer: Leader from the tribe of Dan during the Exodus Ammishaddai: Father of Ahiezer, leader of Dan

Dan: Israelite tribe; city in northern Israel; originally called Laish/Leshem