The clear message of the observations is that the redshift of a cosmic object depends overwhelmingly on the kind of object it is. That is, different objects have different intrinsic redshifts that owe nothing to velocity or to the medium between the object and the observer. In each case, the younger, smaller galaxies in a group have systematically higher redshifts than the older. This suggests that the faint cluster galaxies associated with BL LAC objects are young galaxies in process of evolving into normal galaxies like the Milky Way and its companions. Note first that redshifts are lower frequencies.
Lower frequencies mean slower clocks.
Arp proposes that intrinsically redshifted matter has lower mass than local matter, that each particle of redshifted matter has lower mass than our local particles. Guided by the observation that a quasar's redshift declines as it ages, Arp proposes that quasars are made up of new matter. On this view, matter is continually created in active galaxies, and is episodically ejected in the form of quasars. Each particle starts out with a low mass which increases with its age. Unlike Big Bang supernaturalism, continual creation within an eternal universe does not involve the absurdity of creation from nothing.