en_tn/isa/19/21.md

Yahweh will be known to Egypt, and the Egyptians will know Yahweh in that day

Here "Egypt" refers to the people. AT: "There will be a day when Yahweh will make himself known to the people of Egypt, and the people will all know Yahweh" (See: rc://en/ta/man/translate/figs-activepassive and rc://en/ta/man/translate/figs-activepassive)

will make vows to Yahweh and fulfill them

“will make promises to Yahweh and keep them"

Yahweh will strike Egypt

"Yahweh will punish the people of Egypt"

striking and healing

This can be translated as a new sentence: "He will punish them and then heal them."