# the contributions lifted up to me
"the offerings that people give to me"
# I have given these offerings to you
"I give these offerings to you". The tribes of Israel were required to bring a tithe (offering) to the Levites in order to free them to serve Yahweh as priests. There is a detailed description of what belonged to Yahweh in this chapter.
# as your assigned portion for all time
"as the portion that you will continually receive"