Teth

Teth, also written as Ṭēth or Tet, is the ninth letter of the Semitic abjads, including Phoenician ṭēt 𐤈, Hebrew ṭēt ט, Aramaic ṭēṯ 𐡈, Syriac ṭēṯ ܛ, and Arabic ṭāʾ ط. It is the 16th letter of the modern Arabic alphabet. The Persian ṭa is pronounced as a hard "t" sound and is the 19th letter in the modern Persian alphabet. The Phoenician letter also gave rise to the Greek theta (Θ), originally an aspirated voiceless dental stop but now used for the voiceless dental fricative. The Arabic letter (ط) is sometimes transliterated as Tah in English, for example in Arabic script in Unicode.

The sound value of Teth is, one of the Semitic emphatic consonants.

Origins
The Phoenician letter name ṭēth may mean "spinning wheel" pictured as (compare Hebrew root ט-ו-י (ṭ-w-y) meaning 'spinning' (a thread) which begins with Teth). According to another hypothesis (Brian Colless), the letter possibly continues a Middle Bronze Age glyph named ṭab 'good', Aramaic טַב 'tav', Hebrew 'tov', Syriac ܛܒܐ 'tava', modern Arabic طَيّب 'ṭayyib ', all of identical meaning, whose picture is based on the Nefer 'good' hieroglyph common in ancient Egyptian names (e.g. Nefertiti):

Jewish religious books about the "holy letters" from the 10th century onward discuss the connection or origin of the letter Teth with the word tov "good". This was especially emphasized ever since the late 1600s after the Baal Shem Tov became influential, since the letter Teth was in his Acronym standing for Tov, and goodness was part of his philosophy. The acrostic poems of the Bible use 'Tov' to represent the letter (e.g. Psalm 119:65-72).

Arabic ṭāʾ
The letter is named ṭāʾ طَاءْ; Modern Standard Arabic pronunciation:.

The letter does not change its shape depending on its position in the word:

Hebrew tet
The Hebrew spelling of name of the letter:

Hebrew pronunciation
In Modern Hebrew, Tet represents a voiceless alveolar plosive, and is therefore usually homophonic with the abjad's final letter, Tav ת. However, Tet can be pharyngealized to produce in traditional Temani and Sephardi pronunciation. [tˤ] is also probably the pronunciation in Biblical Hebrew.

Significance
In gematria, Tet represents the number nine. When followed by an apostrophe, it means 9,000. The most common example of this usage is in the numbers of the Hebrew years (e.g., in numbers would be the date 9754).

As well, in gematria, the number 15 is written with Tet and Vav, (9+6) to avoid the normal construction Yud and Hei (10+5) which spells a name of God. Similarly, 16 is written with Tet and Zayin (9+7) instead of Yud and Vav (10+6) to avoid spelling part of the Tetragrammaton.

Tet is also one of the seven letters which receive special crowns (called tagin) when written in a Sefer Torah. See Shin, Ayin, Gimmel, Nun, Zayin, and Tzadi.

Similar symbols
A symbol similar to the Phoenician teth is used for the tensor product, as $$\otimes$$, but this is presumably an independent development, by modification of the multiplication sign ×. The Hebrew is also visually similar to the letter Ʋ.