This morning, before leaving to office, while folding the clothes (an overdue task), I turned on the TV and watched the 'Tanyalah Ustaz' (which I like). There was the 'THE USTAZ ZAMRI' (yang mantop) talking about something like 'Pembersih Jiwa' and he talked about zikr. As it was already towards the end of the program, I was only able to listen to two questions.
1. First questions was about ladies in haidh, whether they can read the Quran.
The answer was NO, if their intention is really to read the Quran. BUT, if they treat the reciting of the Quran as ZIKR, it is allowable especially with those regular verses like the three Quls. It was told that Sayyidatina Aishah (whom a hafizah) used to recite Quran during her menses so that she will not forget what she has memorized. Therefore, it is agreable among the ulama' (jumhur ulama') that the ladies in menses can recite Quran, BUT, not new verses, instead, only those that they had memorized earlier.
2. The second question that I listened to was about the BEST zikr that we could practice daily.
Ustaz mentioned few hadith, and based on the hadiths, it was concluded that the best zikr is the one that you do regularly (without fail). It could be anything as long as you do it with istiqamah. However, there's one Istighfar that is considered as the 'Penghulu Istighfar'. This istighfar if recite daily in the morning and in the afternoon, we are promised Jannah (based on a sohih hadith by Bukhari & Muslim).
This Istighfar is also in the Ma'thurat (the collection of dua' and zikr). The istighfar is as follows: