en_tn_condensed/isa/23/03.md

Upon the great waters was the grain of Shihor

Shihor was the name of a valley near the Nile River in Egypt known for its production of grain. Alternate translation: "The men traveled on the large sea to transport the grain from Shihor in Egypt" (See: rc://en/ta/man/jit/translate-names)

the harvest of the Nile was her produce

The "harvest of the Nile" refers to the grain that was harvested near the Nile River and transported on the river and then to Phoenicia. (See: rc://en/ta/man/jit/figs-possession)

her produce

"its produce." It was common to refer to the river as "her."

it became the commerce of the nations

Commerce is the activity of buying and selling goods. Here "nations" represents the people. Alternate translation: "you were where people from other nations came to buy and sell goods" (See: rc://en/ta/man/jit/figs-metonymy)