Your servants are shepherds
"Your servants shepherd flocks"
Joseph's brothers refer to themselves as "your servants." This is a formal way of speaking to someone with more authority. This can be stated in first person. AT: "We, your servants" or "We" (See: rc://en/ta/man/translate/figs-123person)
as our ancestors
"both we and our forefathers" or "both we and our ancestors"
We come as temporary residents in the land
"We have come to stay for a while in Egypt"
There is no pasture
"There is no grass to eat"
This does not mean "at this moment," but is used to draw attention to the important point that follows.