When you are studying or sitting an exam
The only thing Allah commands His Messenger ﷺ to ask for more of.
فَتَعَـٰلَى ٱللَّهُ ٱلْمَلِكُ ٱلْحَقُّ ۗ وَلَا تَعْجَلْ بِٱلْقُرْءَانِ مِن قَبْلِ أَن يُقْضَىٰٓ إِلَيْكَ وَحْيُهُۥ ۖ وَقُل رَّبِّ زِدْنِى عِلْمًا
Rabbi zidnī ʿilmā.
So high [above all] is Allāh, the Sovereign,1 the Truth.2 And, [O Muḥammad], do not hasten with [recitation of] the Qur’ān before its revelation is completed to you, and say, "My Lord, increase me in knowledge."
Source
The Qur'an · 20:114
Qur'an
- Qur'anic text in the Uthmani script via Quran.com; translation: Saheeh International