اَللَّهُمَّ إِنِّي أَسْتَخِيرُكَ بِعِلْمِكَ، وَأَسْتَقْدِرُكَ بِقُدْرَتِكَ، وَأَسْأَلُكَ مِنْ فَضْلِكَ الْعَظِيمِ، فَإِنَّكَ تَقْدِرُ وَلَا أَقْدِرُ، وَتَعْلَمُ وَلَا أَعْلَمُ، وَأَنْتَ عَلَّامُ الْغُيُوبِ
Transliteration
Allahumma inni astakhiruka bi'ilmika, wa astaqdiruka biqudratika, wa as'aluka min fadlikal-'azimi, fa innaka taqdiru wa la aqdiru, wa ta'lamu wa la a'lamu, wa anta 'allamul-ghuyub
English meaning
O Allah, I seek Your guidance through Your knowledge, and I seek ability through Your power, and I ask You for Your great bounty. For You are able and I am not, and You know and I do not, and You are the Knower of the unseen.
When is it recited?
Recited after praying 2 rakats before an important decision.
Its virtue
Umar said: 'Whoever performs Istikhara will not be deprived.'
Source
Bukhari, Tahajjud 25