Observe here again discriminating mercy. Although the cattle of Israel were under the same climate, breathed the same air, ate of the same herbage, and drank of the same water, yet how different the issue to that of the cattle of Egypt. David's observation is worth perusal, Psalms 36:6. And yet more to the purpose in the application, is that of the Lord Jesus: Luke 12:6-7.
Related Commentaries of Exodus 9:6
Exodus 9:6
6 And the LORD did that thing on the morrow, and all the cattle of Egypt died: but of the cattle of the children of Israel died not one.