Israeli strikes in Lebanon are against Hezbollah fighters who are launching ATGM, mortars, or other munitions into Israel. This particular incident is exceptional in two ways:
This is a relatively senior ranking member who was killed (number 3 in the Radwan Force)
This appears to have been an attack of opportunity rather than a retaliatory strike
Reuters did a shit job on background context here. It took me 20 minutes half paying attention to a meeting that should have been an email to dig this up:
Hezbollah has launched 565 coordinated attacks (usually barrages against multiple targets along the border) on Israeli territory resulting in 4 civilian and 12 military fatalities and many more injured.
Due to the ongoing attacks, over 80,000 Israelis are internally displaced, and all the villages within 4km of the border have been evacuated.