Mandaic is written right to left and joined, as Syriac and Arabic are, so a word is drawn as a connected run. Eight signs do not join to the letter that follows them: halqa, az, it, aksa and ash among the inherited letters, and the three signs that close the alphabet, dushenna, kad and ain. After one of these the pen lifts and the next letter starts a fresh group.
This gives a line of Mandaic its visible structure. Word boundaries in a joined script are marked by spacing, which a cursive hand can reduce almost to nothing, so the breaks inside words are what stop a line reading as one continuous stroke. A reader uses them to segment before recognising any individual letter, and a long Mandaic word can otherwise carry a single unbroken stroke across most of its length.
Syriac has its own list of eight such letters and Arabic has one of six. The three lists overlap without matching, which is exactly what would be expected of three scripts that inherited the same alphabet and then went their own way in how they joined it. Comparing them is one of the few places where the kinship of these scripts is visible in the writing rather than in the order of the letters.
Aksa is on the Mandaic list, and since it is also a vowel letter, its breaks fall wherever an i does, which is often.