اللَّهُمَّ إِنِّي أَسْأَلُكَ عِلْماً نافِعاً وَرِزْقاً طَيِّباً وَعَمَلاً مُتَقَبَّلاً (بَعْدَ السّلامِ مِنْ صَلاَةِ الفَجْرِ
Allāhumma innī as'aluka `ilman nāfi`an, wa rizqan ṭayyiban, wa `amalam-mutaqabbala.
[to be said after giving salam for the Fajr prayer.] "O Allah, I ask You for knowledge which is beneficial, and sustenance which is good, and deeds which are acceptable."
Ibn Majah and others. See Sahih Ibn Majah 1/152 and Majma' Az-Zawa'id 10/111