Is it true that there is an inscription that says that Yahweh had a wife? In this video, around 1:08:40, Amihai Mazar, of the Hebrew University of Jerusalem, says:


  The name "Yahweh", as the name of an Israelite God, [...] appears for the first time in the inscriptions of around 800 BC, found in the Sinai desert, and one of the inscriptions is a dedication to Yahweh and his "asherah": that means, Yahweh, the God of Israel, in this inscription, has a consort, a wife.


Does such an inscription actually exist? Is this a correct interpretation of the inscription in question?
There are inscriptions found in Kuntillet Ajtud and a further inscription found scratched on bedrock in a tomb at Khirbet el-Qom in Judah, that appear to say the goddess Asherah was considered to be the wife of Yahweh. The first of these was discovered in 1975, when Tel Aviv University archaeologist Ze’ev Meshel decided to excavate at remote Kuntillet ‘Ajrud in the Sinai desert. Here they discovered two large pithoi with inscriptions that mentioned Baal, and also Yahweh and his Asherah. Two further references to Yahweh and his Asherah were found on the walls. 

The early Israelite dialect was closer to Phoenician than to that of Judah, creating confusion as to whether the Kuntillet Ajtud inscriptions were written by Phoenician worshippers of Yahweh or by Israelites. Careful linguistic analysis has confirmed these inscriptions to be of Israelite origin. Othmar Keel and Christoph Uehlinger explain in Gods, Goddesses, and Images of God, page 247, the mention of 'Yahweh of Samaria', the fact that the theophoric personal names found at Kuntillet Ajrud are formed without exception using the element -yw (not the Judahite -yhw), the paleographic commonalities that link the pithos inscriptions and the ostraca from Samaria, and the iconographically and epigraphically demonstrable combination of elements of (Syro-) Phoenician and Israelite culture all demonstrate clearly that the caravanserai at Kuntillet Ajrud was not Judahite. It was set up using Phoenician skills but was controlled by Israelites and had no local roots. He says it was probably in use no longer than one generation.

As Khirbet el-Qom is in Judah, presumably the early Judahites shared the belief that Asherah was the consort of Yahweh.