en_tn_condensed/isa/08/05.md

Because this people have refused the gentle waters of Shiloah

These gentle, flowing waters are compared to the teachings of the Lord that were always available to lead the people of Jerusalem. AT: "Because this people have rejected Yahweh's help which is like the gentle waters of Shiloah." (See: rc://en/ta/man/translate/figs-metaphor and rc://en/ta/man/translate/translate-names)

and are happy over Rezin and Remaliah’s son

See how you translated these names in Isaiah 7:1. The full meaning can be made explicit: "and are happy that the armies of Assyria have defeated Rezin, king of Aram, and Pekah, Remaliah's son, king of Israel." (See: rc://en/ta/man/translate/figs-explicit)

therefore the Lord is

Yahweh is still speaking. He refers to himself as "the Lord." AT: "therefore I am."

up on them

"up on the people of Judah"

the waters of the River, mighty and many, the king of Assyria and all his glory

AT: "the army from Assyria that is powerful like a mighty river."