If you’re leading services in a church, synagogue, or other place of worship. Or leading the pledge of alliegance or some other situation of telling people to stand up.
“Please rise if you are able” can be a good thing to say.
Because some people can’t or shouldn’t stand. And it’s good to acknowledge that they’re not doing anything wrong. It’s good to affirm that they are still valued members of the community even when the way they show respect for God doesn’t involve standing.
This should go without saying. But it doesn’t. So it’s good to say it.