How to Complete A Harvest Hand
The objective is to gather as much fruit as you can in four rounds. The law forbids harming the weak, so make sure to choose units that are lower level than the enemy units, or just don't attack them with higher-level units.
To gather fruit, go to a tile next to a tree and choose Gather. There are six fruit trees total. The more fruit you get, the better the reward you get at the end of the quest.
You can make this quest easier by sorting your units by Speed, using the Speed↑ Clan Privilege, using units like Gria who can ignore obstacles, and so on.