Right
麻 supplies the sound — má lightens to toneless ma in the everyday particle use, and the older má reading survives in the niche mantra and Taiwan-colloquial senses.
麻 itself shows hemp stalks under a shelter
广, picturing the workshop where hemp was processed; that meaning is incidental here, the right side is read purely for sound. Same phonetic family includes
妈 (mother),
吗 (question marker), and
玛 (agate).