What does the cryptic crossword clue "Only some of Mughal alphabet is permitted in Islam (5)" mean?

The wordplay uses a hidden word. A hidden answer (‘only some of’) in ‘Mug HAL AL phabet’. The answer is HALAL.

Only some of Mughal alphabet is permitted in Islam (5)

Guardian Cryptic #29394 | 23 Across | 2024-05-28 flower