In D&D 5e, the Glyph of Warding spell allows you to store a spell that is cast on whoever triggers the glyph. The limits on the stored spell are rather vague: "The spell must target a single creature or an area."
This would seem to include the Sending spell, which clearly targets a single creature. How would this work?
My assumption is that:
- When I cast Glyph of Warding, I also cast the Sending spell at the same time (see this question). I assume that I must make any choices about the spell, aside from the spell's target, at that time. In the case of the Sending spell, this would include the message being sent. (Similarly, in the case of a spell like Summon Fey the kind of fey summoned would be chosen when the glyph is cast, not when it is triggered.)
- When the glyph is triggered, the Sending spell gets a target and the casting completes, so whoever triggered the spell gets my saved message.
- The person who triggered the glyph gets to respond to the Sending, and I would hear this message in my head, as usual.
Is this right? Or am I missing some nuance in the mechanics?