This is its interpretation: This points forward to what Joseph is about to say.

The three branches are three days is literally “the three branches three days.” The sense of this expression is that the three branches stand for or symbolize three days.

Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Genesis. (UBS Helps for Translators). New York: UBS, 1997. For this and other handbooks for translators see here .