Invite from atop the stairs, say

ASK UP

Think of a phrase meaning to request someone to come higher, like calling a friend to join you on a balcony.

This clue plays with the idea of "asking someone up" as in inviting them upstairs, like calling to a person from the top of a staircase. The word "up" isn’t just about location—it’s part of the answer, turning the verb "ask" into the phrase "ASK UP." The "say" hints that this is one possible way to interpret the scenario, not the only one.