The Phoenician letter gave rise to the Greek tau (Τ), Latin T, and Cyrillic Т. Taw is believed to be derived from the Egyptian hieroglyph representing a tally mark.
The isolated and final forms of this letter combine the shape of hāʼ (ه) and the two dots of tāʼ (ت).
Bet, kaph and pe have their sound values changed in modern Hebrew from the fricative to the plosive, by adding a dagesh.
The midrash explains that emet is made up of the first, middle, and last letters of the Hebrew alphabet (aleph, mem, and tav: אמת).
Ezekiel 9:4 depicts a vision in which the tav plays a Passover role similar to the blood on the lintel and doorposts of a Hebrew home in Egypt.
[2] In Ezekiel's vision, the Lord has his angels separate the demographic wheat from the chaff by going through Jerusalem, the capital city of ancient Israel, and inscribing a mark, a tav, "upon the foreheads of the men that sigh and that cry for all the abominations that be done in the midst thereof."
In other words, looking askance at a culture marked by dire moral decline is a kind of shibboleth for loyalty and zeal for God.
When the phoneme is marked with a rūkkāḵā dot below the letter ܬ݂ ܬ݂ ܬ݂ indicating 'soft' pronunciation, the phone is spirantized to a fricative /θ/.