My work is pending because I need a permission from someone outside the scrum team. The scrum master knows about this issue because I said that yesterday and today in the stand up. What I'm thinking about is shall I say "There is no update from my side" is that good to say? Or mention the same issue tomorrow (which everyone in the team already knows about)
If your task is blocked, it sounds like you should have a lot to say during the Daily Scrum.
You and your team need to talk about what's going to happen now.
I mean, I'm going to assume that your task wasn't placed on the backlog to keep you occupied. Generally speaking, tasks on the backlog are important. And they are important soon. But the task is not being done, because of an outside issue.
Is your task not getting done threatening your Sprint Goal? If so, you need to talk with your Product Owner and what to do now. You might need to escalate the whole "waiting for permission". Who are you waiting for? How aware are they that this pending permission is blocking your sprint and might cause you not to hit the goal? Is there anyone around who can put some pressure on this person to do their job?
Is your task not getting done not threatening your Sprint Goal? Then mark it as blocked, send the occasional status update to this person and then talk with your team about you'll be doing now. Is there anyone you can lend a hand? Is there any new work that you can pick up? Can you do some admin while you wait? Refine some stories with the PO?
"My work is blocked and I'm not doing anything" should be the furthest from "nothing to say" you can get. In a daily scrum the only reason you might have for having "nothing to say" is "Everything is on schedule, nothing is blocked, we'll meet the goal on time." Any other message is what the Daily Scrum is for.
You need to move from the idea of "my work" to "our work".
In Scrum, individuals do not have work. The team forecasts and plans work in support of a goal. If you took a piece of work as far as you can and are now dependent on someone outside of the Scrum Team, you should work to get that unblocked. This could mean letting the Scrum Master know since one of their responsibilities is to help in removing impediments. It could mean following up with the person or people you are dependent on. Once you've done that, the next step is to help the rest of the team with other work. It could mean starting a new task or helping someone else finish what they are working on.
You shouldn't be waiting until the Daily Scrum to raise impediments or seek out something else to do to help your team. The Daily Scrum does provide a good opportunity to let your teammates know that you may be blocked on progress and you may be able to help them with other things. If you have nothing to say about offering help or making progress, you need to start there.
Ask your boss, or whoever is responsible for running the meeting. Different bosses will have different expectations.
In general it is usually a good idea to say something brief such as:
"I'm waiting for permission from team X, as discussed yesterday.
In the meantime I've taken the opportunity to do Y."
Y could be anything. Helping a colleague, sorting out your emails, catching up on mandatory training, online learning, cleaning out the loos.... whatever. You just need to indicate that your primary objective was blocked but you still tried to achieve something, ideally without boring anyone with too many details.