Shaykh b. Bāz (rahimahullāh) said,
In general, memorisation is from knowledge and fahm is greater and the head and foundation of knowledge is the Qurān.
Therefore whoever desires knowledge then let him contemplate on the Qurān and give importance to the Qurān, in terms of memorisation, contemplation, revision and action upon it.
And the knowledge of the companions, most of it was from the Qurān, some of them did not memorise except a few ahādīth; however Allāh benefited them by their knowledge and their concern with the Book of Allāh (Azza wa Jal).
Shaykh ibn Bāz’s Sharh Kitāb at-Tawhīd min Sahīh al-Bukhāri pg 410-411