You do have the right to ask why they want to meet with you.
Just do it in a surprised “oh is something wrong” concerned manner.
If the elder asks why you want to know why say, “you know how I always want to help, but I’m really busy right now and am exhausted, so if someone else could step in just this one time you’d really appreciate it”.
I’ve used this one and, if done correctly, works extremely well because it shows your “deep concern, willingness and appreciation” while throwing the ball back it their court in a nice killing ‘em with Christian love way.