Jeff
Nice cover!
This miniature sheet, Israel's second, was issued to coincide with the Tabil International Exhibition in Tel Aviv. It contains 4 triangular stamps, rouletted.
Depicted on the sheet is a Mosaic from the floor of the Ancient Synagogue of Bet Alfa near Mount Gilboa in the Jezreel Valley. It was discoverd during excavations in 1929.
What you have is an official show cover, unaddressed, issued by Israel Post on the Day of Issue. The show Logo is top left corner while the Israel Post logo is bottom right.
Running stags everywhere, also on the show cancels !

Londonbus1