What is the meaning of "al-ḥadd al-ḥāṣil" (the actual limit) which Ibn 'Uthaymeen negated in the context of proving that Allah is distinct from His creation?

The correct phrase is "al-hadd al-hasir" (the circumscribing boundary), not "al-hadd al-hasil" (the obtained boundary). It means negating that Allah has a boundary that encloses Him. The Salaf differed on the issue of Allah's boundary, and the disagreement is semantic: those who affirmed the boundary intended His distinctness from His creation, which is correct. And those who negated it intended that Allah is not encompassed by His creation, which is also correct. The author, by negating the boundary, intended the boundary that encloses Allah Almighty, not the boundary that makes Him distinct from creation, for Allah's distinctness from His creation is a firmly established matter. It is appropriate to refrain from speaking about the boundary, whether in affirmation or negation, due to its absence in sacred texts, except when there is a need for clarification.