Does sleeping after fajr and asar weaken your memory ?

We have not come across any narration to this effect.

However, in the Ahaadith, we are informed that these two times are very blessed and should preferably be spent in the Dhikr of Allah Ta'ala. Furthermore, the time between Asr and Maghrib is short. There is a fear that one who sleeps after Asr may miss his Maghrib with Jamaat. Thus, without a strong need, one should avoid sleeping during these two times.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai
FATWA DEPT.