1)
Why did the brothers need to prepare the gift?
1.
Rashbam: Because, due to the traveling, the beauty of the fruit was diminished.
2)
"Ki" implies that they prepared the gift because they heard... How is this? In any case they would give the gift!
1.
Ha'amek Davar: They knew that usually Yosef came at three hours after midday. They heard that he will eat with them at noon, so they rushed to prepare it before then.
QUESTIONS ON RASHI
3)
Rashi writes: "'They prepared [the gift]' - They made it ready; they decorated it using beautiful vessels." Why interpret this way?
1.
Gur Aryeh: They had brought the gift with them ready from the land of Kena'an; they could not 'make it ready' in the usual sense.