(Paul explains why it is important to provide for Zenas and Apollos.)
## set before themselves ##
"be busy doing"
## so that they may not be unfruitful ##
This double-negative can also be stated positively: "so they will be fruitful" or "so they can produce fruit for God" or "so their lives will be useful." (See: [[rc://en/ta/man/translate/figs-doublenegatives]])