ON. [z] became [i] before [d], [g] and [u] before [b]; [z{bdg}] > [i{bdg}]

ON. [z] became [i] before [d], [g] and [u] before [b]; [z{bdg}] > [i{bdg}]
See OS. [z] vanished before [d] lengthening preceding vowel for discussion.

References ✧ PE22/25-26, 29

Order (02500)

After 02400 long final vowels were shortened ᴹ✶EZDĒ > Ezde > Eide > ON. Īde Ety/EZDĒ
Before 03200 [ei], [ou] became [ī], [ou] ᴹ✶EZDĒ > Ezde > Eide > ON. Īde Ety/EZDĒ

Related

Phonetic Rule Elements

[zb] > [ub]
[zd] > [id]
[zg] > [ig]

Phonetic Rule Examples

ezde > eide zd > id ᴹ✶Ezdē > ezd > ēd > N. Īð ✧ PE19/45
ezde > eide zd > id ᴹ✶EZDĒ > Ezde > Eide > ON. Īde ✧ Ety/EZDĒ
mizde > mīde zd > id ᴹ✶mizdē > N. mídh ✧ Ety/MIZD
rezda > reida zd > id ᴹ✶reddā/red-tā > N. rîð ✧ EtyAC/RED
mazga > maiga zg > ig ᴹ✶mazgā > mazga > ON. maiga ✧ Ety/MASAG
mazge > maige zg > ig ᴹ✶mazgē > mazge > ON. maige ✧ EtyAC/MASAG