You know that I have served your father with all my strength: You (plural) is emphatic in the Hebrew construction. See Good News Translation “You both know.” In languages that have dual pronoun forms, this will be “You-two know.” With … strength is sometimes rendered idiomatically as “I worked for your father with my body and my heart” or “… with my hands and my feet.”

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 .