From Wiktionary, the free dictionary
ασ' • (as')
- Contraction of άσε (áse, “let, leave”).
Ασ’ την ήσυχη.- As’ tin ísychi.
- Leave her alone.
Ασ’ τους να λένε.- As’ tous na léne.
- Let them go on talking.
Used in place of άσε (áse) when the next word starts with ⟨τ⟩.