Does an oath become binding with the phrase "ثقة بالله" (trusting in Allah), or is it an exception like "إن شاء الله" (if Allah wills) when speaking about a future matter?

A person's statement: "Trusting in Allah, I will do that," is not an oath, but rather a seeking of blessing and reliance upon Allah, and it does not necessitate an expiation for breaking an oath. An oath that requires expiation is one made by a name of Allah, or one of His attributes, or by the Quran, or by a surah or a verse from it. What is legislated when intending to do something in the future is to say "Insha'Allah" (if Allah wills), in accordance with His saying, the Most High: "And never say of anything, 'Indeed, I will do that tomorrow,' Except [by adding], 'If Allah wills.'"