Devarim 1:34

³⁴ וישמע יהוה את־קול דבריכם ויקצף וישבע לאמר׃

Euphrates

In Genesis 2:14 and Psalms 80:9, 10, the Euphrates symbolizes secular knowledge — facts — and the sensory impressions on which facts are based. (Secrets of Heaven 120)

¹⁴ The name of the third river is Hiddekel: this is the one which flows in front of Assyria. The fourth river is the Euphrates.