Question:

We read in the Bible (Exodus 9:6) that after the fifth plague that the Egyptians endured, “All the cattle of Egypt died.”

Then the next plague (ibid verse 10) is said to affect the livestock. Were they all dead or not?

Answer:

Rashi, a primary biblical commentator, asks this question in his commentary on the verse 9:10.

He explains that the plague of pestilence only struck those animals that were out in the fields, as Moses warned Pharaoh (in verse 4), "The hand of the L‑rd will be upon your livestock that is in the field."

The Egyptians who took Moses' warning seriously, and feared G‑d, brought their animals inside, and those animals were spared.

So what does it mean that the Egyptians’ cattle died? Of the animals in the field, only those belonging to the Egyptians died. The animals belonging to the Jews, even those in the field, did not die.

Please see the Ten Plagues.