O son, today we learned this du'a from watching telly - a simple but important du'a. It's a well known du'a to many people but I wish to record it here for you. And I thank Allah shukran lillah for He has made it easy to memorize so many meaningful du'a ever since I re-embraced Islam. Alhamdulillah indeed.
According to the Ustaz in the tv program, it's a du'a Prophet Muhammad s.a.w had recited for Ibn Abbas so he could master the Qur'an with much ease and excellence.
If you were to recite it for yourself say it this way:
Allahumma faqihna fiddinwa ‘allimna takwil
If you wish to recite it for someone else say:
Allahumma faqihhu fiddin wa ‘allimhu takwil
Apparently there is an extended version of this du'a but we present it exactly as we've heard it InshaAllah.
Rabbi zidni 'ilma.