Tel Aviv doesn't want an end to hostilities if it doesn't come with sweeping concessions to Israeli interests
During his visit it France, Israeli PM Benjamin Netanyahu told the press Israel "was totally opposed" to the US-Russian brokered ceasefire for southern Syria because it "perpetuates Iran’s military presence in Syria".
Actually the text of the ceasefire agreement does not mention Iran with a single word. That is exactly what the problem is for Israel:
“The agreement as it is now is very bad” one senior Israeli official said. “It doesn't take almost any of Israel's security interests and it creates a disturbing reality in southern Syria. The agreement doesn’t include a single explicit word about Iran, Hezbollah or the Shi’ite militias in Syria.”
Netanyahu opposes the deal because it doesn't explicitly spell out that Hezbollah and Iran are to be barred, not just from southern Syria, but the entire country, but it's difficult to see that as a reasonable demand. We're talking about a truce here, not a comprehensive peace agreement. It is scarcely reasonable to demand retreat as a condition for a simple ceasefire.
By definition a cease fire is with whoever is on the other side.
We can note that Damascus is not opposed to the ceasefire deal albeit parts of southern Syria on the line of contact with Israel are held by ISIS and al-Qaeda. Yet the Syrian government has not demanded the retreat of these groups—which Israel misses few opportunities to show favor for—as a condition for a cessation of hostilities.
What we really have here is Israel trying to tack on sweeping strategic concessions to Israel's interests, onto a simple cease fire deal between factions in the Syrian civil war. Guarantees which are totally tangential to the ceasefire and unnecessary for its success.
The good news is that the Trump administration in the end seems to have decided it was not going to indulge Israel to the point of burying the ceasefire deal for its sake. Trump in his own earlier visit to France praised the deal:
One of the great things that came out if this meeting, by the way, was the fact that we got the ceasefire that now has lasted for almost five days. Five days doesn’t sound like a long period of time. In terms of a ceasefire in Syria it’s a very long period of time."
"That was a result of having communication with a country. During that five day period a lot of lives have been saved, a lot of people were not killed, no shots have been fired in a very, very dangerous part of the world and this is one of the most dangerous parts of Syria itself.
“By having some communication and dialogue we were able to have a ceasefire and it’s going to go on for a while. And frankly we’re working on the second ceasefire in a very rough part of Syria.”
These words signifying Trump owned the ceasefire may have been exactly what caused Netanyahu to blow over and make his opposition public. He'll now be hoping that neocons, arch hawks, and the pro-Israel lobby can discipline Trump and get him back in line.
Israel also claims Iran plans permanent military bases in Syria which is the first we've heard of it. According to a senior Israeli official Haaretz spoke to "this already changes the picture in the region from what it has been up to now." That is true, but it is also something Israel should have thought about before it looked on with glee as the Saudis, Americans and Turks plunged Syria into a jihadist insurgency.