Is the statement of one who says that Allah is a body, but not like other bodies, because "there is nothing like Him," sound according to Islamic law? What is the ruling of Islamic law concerning it? And what is our duty regarding this statement and its utterer?

The statement that Allah is a body unlike other bodies is incorrect, because the description of Allah the Almighty as having a physical form (corporeality) has not been mentioned in the Qur’an or Sunnah. The fundamental principle among the Ahl al-Sunnah wal-Jama’ah (mainstream Sunnis) is to describe Allah only with what He has described Himself, or what His Messenger has described Him with, without exceeding that.

The word "body" (Jism) is ambiguous; it may refer to something impossible for Allah, such as fragmentation or composition, or it may refer to something permissible to affirm for Him, such as visibility (Ru'yah) and pointing to Him. Shaykh al-Islam Ibn Taymiyyah clarified that the term is an innovation, whether in negation or affirmation, and it has not appeared in the sacred texts, hence it must be avoided.

One who makes such a statement is advised to adhere to the methodology of the righteous predecessors (Salaf Sālih), and to describe Allah with what is mentioned in the Qur’an and Sunnah without distortion, nullification, anthropomorphization (takyeef), or similitude (tamtheel).