قَالُوا۟ سَنُرَٰوِدُ عَنْهُ أَبَاهُ وَإِنَّا لَفَـٰعِلُونَ
Qaaloo sanuraawidu 'anhu abaahu wa innaa lafaa'iloon
They said, "We will try to coax his father into letting him come, and we will surely do it."
Sanurāwidu is the surah's own loaded verb, used three times already for the wife of the ʿAzīz working on Yusuf, and the brothers now use it of their father. Rāwada names persistent pressure applied to someone who does not want to give in, and the construction here is identical: to work on a person about something. They promise the effort, and the certainty they add covers only their trying.