en_tn_condensed/deu/03/02.md

Sihon

This is the name of a king. See how you translated it in Deuteronomy 1:4.

Heshbon

This is the name of a city.

Yahweh said to me, 'Do not fear him; ... given you ... under your control ... You will do ... as you did ... at Heshbon.'

Yahweh is speaking to Moses as if Moses were the Israelites, so the command "do not fear" and all instances of "you" and "your" are plural.

fear him ... over him ... his people and his land

Here the words "him" and "his" refer to Og.

I have given you victory

Yahweh speaks of what he will do as if he had already done it.

You will do to him as you did to Sihon

"You will destroy Og and his people as you did Sihon"