This chapter has many great names, each one indicating a different aspect of its meaning. In the eyes of the Arabs if a thing has many different names, was an indication of its importance. (as-Suyuti al-Itqan vol 1 pg 116)
It is named al-Fatihah, the Opening – because it opens the Book and by it the recitation in prayer commences.
It is also named Ummu-l-Qur’an, the Mother of the Qur’an, and Ummu-l-Kitab, the Mother of the Book, according to the opinion of the majority. This was mentioned by Anas, however al-Hasan and ibn Sirin disliked this appellation, reasoning that this was the most fitting description for the Preserved Tablet. Al-Hasan also said that the unequivocal verses of the Qur’an comprised the Mother of the Book. However, it is established in at-Tirmidhi on the authority of Abu Hurayrah that the Messenger of Allah, may Allah’s peace and blessings be upon him, said,
“[The chapter commencing with] ‘All praise and thanks are due to Allah the Lord of the Worlds’ is the Mother of the Qur’an, the Mother of the Book, the Seven Oft-Repeated Verses and the Great Qur’an.” (at-Tirmidhi 3124)
Bukhari said in the beginning of the Book of Tafsir in his Sahih, “It is named Ummu-l-Qur’an because it is the first chapter written in the Qur’anic texts and the recitation in prayer commences with it.” (Bukhari vol 6 pg1)
Ibn Jarir at-Tabari said that it was named so because the meaning of the entire Qur’an is summarised therein. The Arabs named anything that concisely summarises something or comprises its most important part, Umm, or mother.
For similar reasons it is also named al-Qur’an al-Azim, the Great Qur’an.
It is also named Sab’u-l-Mathani, the Seven Oft-Repeated Verses, because they are frequently recited and indeed recited in every rakah of the prayer.
It is also named al-Hamd, the Praise, because it contains mention of hamd just as al-Baqarah is named so because it contains mention of the cow. Some scholars also gave the reasoning that al-hamd comprises the heart of al-Fatihah. (as-Sindi Sharh as-Sindi ala ibn Majah 3790)
It is also named as-Salah, the Prayer, due to his, may Allah’s peace and blessings be upon him, saying, while reporting from his Lord,
“I have divided the prayer between Myself and my servant equally. Therefore when the servant says, ‘All praise and thanks are due to Allah, the Lord of the Worlds’ Allah says, ‘My servant has praised Me…” (Muslim 775)
It is named the Prayer because its recitation is a condition for the validity of the prayer.
It is also named ash-Shifa, the Cure, due to what ad-Darimi reports on the authority of Abu Sa’id that the Messenger of Allah, may Allah’s peace and blessings be upon him, said,
“The opening of the Book is a cure for every poison.” (Bayhaqi 2368)
It is also named ar-Ruqya, the Spiritual Cure, due to the hadith of Abu Sa’id recorded by Bukhari that after he had recited it to cure a person who had been bitten by a scorpion, the Messenger of Allah, may Allah’s peace and blessings be upon him, asked him,
“…and what made you know it was a ruqya?” (Bukhari 476)
Ash-Shabi records on the authority of ibn Abbas that he named it Asusu-l-Qur’an, the Foundation of the Qur’an, and that he said, ‘the foundation of al-Fatihah is, ‘with the Name of Allah, the All-Merciful, the Most-Merciful’. This is because just as al-Fatihah summarises within it the meaning of the whole Quran, the whole meaning of al-Fatihah is summarised by this statement, as will be shown later.
Sufyan bin Uyaynah named it al-Wafiyah, the Fulfillment, reasoning that it is not possible to apportion it into various parts when reciting or summarising it.
It is also named al-Kanz, the Treasure; ash-Shukr, Gratitude; ad-Du’a, Supplication; ash-Shafiyah, the Sufficient Cure; and al-Waqiyah, the Protection as mentioned by al-Baqai.
The Spiritual Cure: An Explanation of Surah Al-Fatihah prepared and translated by Abu Rumaysah Pages 22-26