If a clock indicates the moment, what does eternity indicate?

The entire dimension we refer to as time.

A clock has fooled everyone into thinking that time is numerical.

A clock can not indicate a moment it can only indicate a relative moment as a it is a condition of a particular observer in relation to his or her motion.
Eternity would indicate the elimination of a contextual meaning of sequintual events or moments.

Eternity doesn't "indicate" anything! It is a state of timelessness.

Confusing question indeed! 'Moment' & 'Eternity' are all right meaning a kind of TIME, but a "Clock" is an instrument! You could ask, if 'moment is shown by clock, then which one shows 'Eternity'? Or you could keep your question's first portion ( "clock indicates time") & could ask what instrument indicates Eternity?

an hour glass

both are measurements of time; while the clock indicates quantified (measured) time relative to the 24hr/12month system, eternity is an "assumed" constant of time that is not restricted by any systems.