Emphatic S & D

It is produced by pressing the tongue against the palate instead of the teeth, giving a heavy, deep "s." The book transcribes it with an underdotted "s." It is a sun letter in Arabic.

The letter ص is a connector: it joins to the letters on both sides. It looks the same as ض (Dad) but ص has NO dot, while ض has ONE dot above.

Hamzat-l-wasl (the joining Hamza): An Arabic word never begins with a vowelless letter. When one would, a Hamza on an alif is placed in front to carry a helping vowel, e.g. اُكْتُبْ ("uktub," write!) instead of كْتُبْ. This beginning Hamza is pronounced only when the word starts a sentence. Inside a sentence its Hamza and vowel drop, and the sign wasla ( ٱ ) is written over the alif; the alif is then silent and merely joins the words. For example قَالَ اُكْتُبْ is read "qaala-ktub," and فِي الْبَيْتِ الْكَبِيرِ is read "fi-l-bayti-l-kabeer." This joining Hamza is called Hamzat-l-wasl.

ص is a SUN letter. With the article ال the "l" assimilates and doubles the ص: الصَّدِيق is pronounced "as-sadeeq," not "al-sadeeq."