What is the ruling on the validity ('sihhah') of a contract for measured or weighed items before possession?

Primary text

The statement 'it is not valid' (laa yassah) likely means that the obligation is not established until possession. Ownership follows the ruling of the gift; therefore, validity pertains to the legal effect. The term 'validity' (sihhah) meaning the linguistic confirmation such that when possession is added, its effect is established, should not be negated because there is no dispute on this point. This interpretation is supported by connecting the ruling to sale contracts ('bay'), where the sale of measured or weighed goods is valid before possession, though liability and absolute disposition are suspended.