en_tn/2sa/17/21.md

It came about

"It happened"

Jonathan and Ahimaaz

See how you translated these men's names in 2 Samuel 15:27.

cross quickly over the water

Here "the water" refers to the Jordan River. (See: rc://en/ta/man/translate/figs-metonymy)

has given such and such advice

This refers to what Ahithophel advised Absalom, which is recorded in 2 Samuel 17:1. So, the writer does not repeat that here. AT: "has advised that Absalom send him to attack you now." (See: rc://en/ta/man/translate/figs-idiom)

By morning daylight not one of them had failed to cross over the Jordan

AT: "By morning daylight they had all crossed the Jordan." (See: rc://en/ta/man/translate/figs-litotes)