((اللَّهُمَّ إِنِّي أَسْأَلُكَ عِلْماً نافِعاً، وَرِزْقاً طَيِّباً، وَعَمَلاً مُتَقَبَّلاً)) بَعْدَ السّلامِ مِنْ صَلاَةِ الفَجْرِ.
O Allah, I ask You for knowledge which is beneficial and sustenance which is good, and deeds which are acceptable. (To be said after giving salam for the fajr prayer)
Ibn Majah and others. See Sahih Ibn Majah 1/152 and Majma' Az-Zawa'id 10/111