Why have the Ash'aris limited the obligatory attributes of Allah to only seven, while other books like "As-hal al-Masalik" and "Matn Ibn Ashir" mention more than seven attributes?

The Ash'aris divided the attributes into the following categories: the essential attribute (which is existence), the negative attributes (which are pre-eternity, subsistence, dissimilarity to created things, self-subsistence, and oneness), the attributes of meaning (which are power, will, knowledge, life, speech, hearing, and sight), and the spiritual attributes (which are His being Powerful, His being Willing, etc.).

The Ash'aris did not affirm the attributive descriptions, such as the Hand and the Face, nor the voluntary actions, such as settling and descending. Instead, they interpreted or consigned them to Allah's knowledge.

The creed of the People of the Sunnah and the Community (Ahl al-Sunnah wa al-Jama'ah) is to affirm what Allah the Almighty affirmed for Himself, or what His Messenger, may Allah's prayers and peace be upon him, affirmed for Him, without interpretation, negation, anthropomorphism, or similitude. They do not restrict the attributes to a specific number.