What happens to Tayammum and prayer if the time for prayer expires while the person is praying using Tayammum?

Primary text

If the prescribed time for the prayer expires while the person is engaged in that prayer following Tayammum, both the Tayammum and the prayer become invalid. This occurs because the ritual purity granted by the Tayammum ceases upon the expiry of its time, thereby invalidating the prayer, analogous to the expiry of the duration for wiping over leather socks (Khuff).