This refers to collecting money for the believers in Jerusalem. AT: "For this task of collecting money" (See: [[rc://en/ta/man/translate/figs-explicit]])
Since the Corinthians are acting in the present time, it is implied that the believers in Jerusalem will also help them at some time in the future. AT: "This is also so that in the future their abundance may supply your need"
# as it is written
Here Paul quotes from Exodus. This can be stated in active form. AT: "as Moses wrote" (See: [[rc://en/ta/man/translate/figs-activepassive]])
# did not have any lack
This can be stated positively. AT: "had all he needed" (See: [[rc://en/ta/man/translate/figs-doublenegatives]])