The quest is unlocked after completing the Each Step Like Thunder scenario.
"The Rito are on a training mission in the Hebra Mountains, but since they ran through their supply of rations, it hasn't been going well. Maybe Link ought to trek up there with some supplies..."
"After eating their fill, the RIto could focus much better on their training! Rumor has it that the day ended with an epic mock battle led by Teba and a certain Hylian courier."
- Teba: Bonus Combo