What is the ruling if rain ceases during the first prayer but returns before its completion, or ceases after commencing the second prayer?

Primary text

If the rain ceases during the first prayer and then returns before finishing it, or if it ceases after commencing the second prayer, the combination remains valid. The cessation does not invalidate the combination because the excuse existed at the time of intention (commencing the first prayer) and at the time designated for combination (the end of the first and beginning of the second).