Wasla

The waṣla (Arabic ‏وَصْلَة‎ "an instance of connection") or hamzatu l-waṣli (هَمْزَةُ ٱلْوَصْلِ "hamza of connection") is a Arabic diacritic resembling part of the letter ṣād (ص) that is sometimes placed over the letter alif at the beginning of the word (ٱ). The alif with waṣla over it is called the alifu l-waṣli (اَلِفُ ٱلْوَصْلِ) "alif of connection". It indicates that the alif is not pronounced as a glottal stop (written with the letter or diacritic hamza ء), but that the word is connected to the previous word (like liaison in French). The waṣla is usually not written, though this incorrect.