* But thou shalt.
   The extirpation of any species of birds, whether edible or
   birds of prey, is often attended with serious consequences,
   and is always productive of evil; to prevent which was the
   object of this law.  Palestine is situated in a climate
   producing poisonous snakes and scorpions, and between deserts
   and mountains, from which it would be inundated by them, as
   well as with immense swarms of flies, locusts, and mice, if
   the birds which feed upon them were extirpated.  In a moral
   point of view, it may have been intended to inculcate a spirit
   of mercy and kindness, and to prevent the exercise of cruelty
   even towards a sparrow; for he who is guilty of such cruelty
   will, if circumstances be favourable, be cruel to his
   fellow-creatures.

 * that it may.
  4:40 
 * thou mayest.
  Pr 22:4