In addition to direct statemenst by Netanyahu, as mentioned in @janh's answer, there was biting criticism from his Foreign Ministry (starement by Israeli Foreign Ministry's spokesperson, Emmanuel Nahshon on July 9, 2017).
While individual Israeli ministers are known to go off the box and express personal views differing from PM, but this was an official Minstry statement so it probably had Prime Minister's approval:
This was the sole purpose of the statement issued by Israel’s ambassador to Hungary. In no way was the statement meant to delegitimize criticism of George Soros, who continuously undermines Israel’s democratically elected governments by funding organizations that defame the Jewish state and seek to deny it the right to defend itself.
In general, Soros is not popular among Israeli right. Netanyahu's son (not known for his polish) posted anti-Soros cartoons which caused controversy.
This article in Mosaic Magazine published an extended article explaining why many Israelis dislike Soros. It's not merely the currently-flared-up issue of Soros's support for illegal aliens that Netanyahu's government wants to remove from Israel and Soros actively works against removal of.
It's general extensive support for NGOs and other organizations seen as undermining Israel, including anti-semitic ones (see the article for details).
This Bloomberg article "A Soros Plan, a Marginalized Israel" details one such set of issues.
Here's another one laying out grievances that many Israelis have with Soros.
Similar, Observer's piece "Not Shocking: George Soros Funds Progressive War on Israel", while it does sound like a hit piece on Soros, lays out many facts like that.