I doubt Israel asked for more time. My guess is that Israel wanted to limit the body count, and decided that plan B would stop the rockets for the forseeable future, and that Hezbollah rearming would now violate a UN resolution, and give it a longer leash in the future, if such is the case. One can criticize that, but then it is not our relatives at risk.
Hezbollah was already violating a UN resolution and they will violate many more, including tonight by the rocket attack. No one cares.