This was spotted at the demonstration against Israeli genocide in Barcelona last month.
It's written in Catalan and reads:
When the Nazis came for the communists,
I remained silent;
I was not a communist.
When they locked up the social democrats,
I remained silent;
I was not a social democrat.
When they came for the trade unionists,
I did not speak out;
I was not a trade unionist.
When they came for the Jews,
I remained silent;
I was not a Jew.
When they came for me,
there was no one left to speak out.
Now they are coming for the Palestinians
and now its our time to speak, boycott, demand expulsions, act!