Why Bismillah Not Recited With Surah Fatiha?
As for Quran 15:87 : The surahs of the Quran are not haphazardly compiled as is generally thought. They have been arranged in a specific order by the Almighty, and like the arrangement of the verses within a surah, the arrangement of the surahs within the Quran is very apt and meaningful with relation to the topic they discuss. In a nutshell, as per this arrangement, the Quran is divided in seven distinct groups and the surahs within each group occur in pairs. This pairing of the surahs is on the basis of the topics discussed, and each member of a pair has a complementary relation with one another. Some surahs are an exception to this scheme like Surah Fatihah, which is like an introduction to the whole Quran. Some other surahs have come as a supplement or as a conclusion of a group. This scheme, with its seven surah-groups and pairing of the surahs, is stated by the Quran in the following words: وَلَقَدْ آتَيْنَاكَ سَبْعًا مِنْ الْمَثَانِي وَالْقُرْآنَ الْعَظِيمَ And [O Prophet!] We have bestowed upon you seven mathani* which is this great Quran . (Quran 15:87) ( * Mathani (مثاني) is the plural of mathna (مثنى) and it means something which occurs in pairs ). For Detailed Discussions on the topic, please refer to the following response/thread : Discussion 52898 • Reply 52912 Discussion 56112 __ For short comments , please refer to the video below from 33:19 to 42:40 https://youtu.be/DKsJ_SlcR4A?t=1999