Which mortgage clause prevents someone from assuming a loan?

The due on sale clause, prevent someone from assuming a loan. This a clause in a loan or promissory that require the full balance of the loan be called due (repaid in full) upon transfer or sale of ownership of property used to secure the note. The lender has the right to call the note due.

The mortgage that prevents someone from assuming a loan is the alienation clause. It is because not only it function of preventing an individual from assuming a loan but it occurs during the upon sale of the lender’s property in which makes the loan immediately in due.