Cast an artifact in your hand by paying {0}.
Teshar triggers, returning Glint Hawk from your graveyard to the battlefield.
When Glint Hawk enters, it triggers, returning another artifact that can be cast for {0} from the battlefield to your hand.
Resolve the artifact spell cast in step 1.
Activate Ashnod's Altar by sacrificing Glint Hawk.
Repeat.

Infinite LTB

Infinite ETB

Infinite sacrifice triggers

Infinite death triggers

Infinite colorless mana

Infinite storm count

Artifact with MV = 0

Teshar, Ancestor's Apostle

Glint Hawk

Ashnod's Altar

Cast Glint Hawk by paying {W}.
Mirrodin Besieged triggers, creating a 1/1 Myr artifact creature token.
Activate Phyrexian Altar by sacrificing a Myr, adding {W}.
Glint Hawk enters the battlefield, returning itself to your hand.
Repeat.

Encroaching Mycosynth

Mirrodin Besieged

Phyrexian Altar

Cast Glint Hawk without paying its mana cost.
Glint Hawk enters the battlefield, returning itself to your hand.
Repeat.

Mycosynth Lattice

Aluren

Cast Glint Hawk by paying {W}.
Efficient Construction triggers, creating a 1/1 Thopter artifact creature token.
Activate Phyrexian Altar by sacrificing a Thopter, adding {W}.
Glint Hawk enters the battlefield, returning itself to your hand.
Repeat.

Efficient Construction

Combos with "Glint Hawk"