Al-jawab billahi at-taufeeq (the answer with Allah’s guidance)
Improving ones memory, one must:
1) Keeping away from sin, because the bad effects of sin result in a bad memory and the inability to retain knowledge. The darkness of sin cannot co-exist with the light of knowledge. The following words were attributed to al-Shaafa’i, may Allaah have mercy on him:
“I complained to [my Shaykh] Wakee’ about my bad memory, and he taught me that I should keep away from sin. He said that knowledge of Allaah is light, and the light of Allaah is not given to the sinner.”
2) Do not eat too much, because eating too much makes one sleep too much and become lazy, and it dulls the senses, besides exposing one to the risk of physical diseases. Most of the diseases which we see result from food and drink.
Also, too much acidic food is one of the causes of laziness and weak memory.
3) Some of the scholars have mentioned certain foods which increase the memory, such as drinking honey and eating raisins and chewing certain kinds of gum resin and nuts such as, almonds.
Imaam al-Zuhri said: “You should eat honey because it is good for the memory.”
He also said: “Whoever wants to memorize hadeeth should eat raisins.” (From al-Jaami by al-Khateeb, 2/394).
4) Another thing that can help the memory and reduce forgetfulness is cupping (Hijaamah) of the head, as is well known from experience. (For more information see Al-Tibb al-Nabawi by Ibn al-Qayyim).
5) Frequently remembering Allaah, may He be glorified, by reciting Dhikr, Tasbeeh (saying Subhan Allaah), Tahmeed (Al-hamdu Lillaah), Tahleel (Laa ilaaha ill-Allaah) and Takbeer (Allaahu Akbar), etc. Allaah Ta’ala says (interpretation of the meaning): “And remember your Lord when you forget” [al-Kahf 18:24] .
6) Recite: ربى زدنى علما
Transliteration: ‘Rabbi Zidni Ilma’
Translation: ‘O my Lord, increase my knowledge’
It may be recited as many time as possible. (Aamale Qurani)
Or recite the Du’a below, twenty times after the morning prayers. (Aamale Qurani) :
رب اشرح لى صدرى و يسرلى امرى واحلل عقدة من لسانى يفقهو قولى
Transliteration: ‘Rab-bish-rahlee Sadree wa-Yassirlee Amree Wa-hlul U’qdatam Mil-lisaanee Yafqahu Qaulee’
(Musa) said: “O my Lord! Expand me my breast; Ease my task for me; And remove the impediment from my speech. So they may understand what I say” (Ta Ha, 25:28)
And Only Allah Ta’ala Knows Best.
Moulana Qamruz Zaman