Religious father figure rabbi had to disrobe (4)

I believe the answer is:

abba

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'religious father' is the definition.
'abba' can be an answer for 'father' (I've seen this before). I'm not certain of the 'religious' bit.

I can't explain the rest of the clue.

Can you help me to learn more?

(Other definitions for abba that I've seen before include "6 24 113 [SCAN-DIN-AVIAN] band" , "Biblical pop" , "famous pop group" , "Palindromic Swedish pop group who sang ` `Waterloo' '" , "Father (used of God in New Testament) - Swedish band" .)

I've seen this clue in The Guardian.

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