رَبَّنَا آتِنَا فِي الدُّنْيَا حَسَنَةً وَفِي الْآخِرَةِ حَسَنَةً وَقِنَا عَذَابَ النَّارِ
Rabbana atina fid-dunya hasanatan wa fil-akhirati hasanatan wa qina 'adhaaban-nar
Nosso Senhor, dá-nos o bem neste mundo e o bem no Além, e protege-nos do castigo do Fogo.
Comprehensive dua that can be said before salam or anytime
This was the most frequent dua of the Prophet (PBUH), asking for good in both worlds.