How to stop system updating once the rooted,unlocked phone tries the OTA update?

My phone is rooted, unlocked
Today Moto has an new update showing up
I accidentally hit "Yes, I am in" to start the update

Now my phone becomes:
-- Booting into TWRP
-- I reboot it to normal, but it starts updating automatically again, then booting into TWRP
-- Repeat above forever....

Before anyone release the update image so I can update it through TWRP, what else can I do to stop it loop like this so I can use my phone???

Thanks in advance!