Comparative evidence

h₁ei̯sh₂, h₁ei̯s

• OInd. iṣ- 'send' (Whitney 1885: 9); 'seek', 'search'; 'cause to move quickly', 'let fly', 'throw', 'cast', 'swing'; 'send out', 'send off', 'stream out', 'pour out', 'discharge'; 'deliver' (a speech), 'announce', 'proclaim'; 'impel', 'incite', 'animate', 'promote' (MW: 168)

• OInd. iṣ- 'moving quickly', 'moving speedy' (MW: 168)

References

MW = Monier-Williams, M. 1899. A Sanskrit-English Dictionary. Clarendon Press.
Whitney 1885 = Whitney W. D. 1885. The roots, verb forms and primary derivatives of the Sanskrit language. A supplement to his Sanskrit grammar. Leipzig.