What does Exodus 5:6 mean?

Moses and Aaron have just asked Pharaoh to let his enormous population of Israeli slaves take time off for worship (Exodus 3:18). They claimed this was a command from God—which it was (Exodus 3:10). Pharaoh has refused (Exodus 5:1–4). Their request seems to have annoyed him. He has begun wondering if he isn't being cruel enough to the Hebrews (Exodus 5:5). Without delay, he issues a command to the "taskmasters" and "foremen" of the Israelites.

Egyptians given power over Israelites as slave managers are referred to as "taskmasters," from the Hebrew word nōgesim'. This may also be translated as "oppressors" or "tyrants" (Exodus 3:7). The root word implies being forcefully pushed towards something. In English, the stereotypical image of someone armed with a whip, forcing captives to work is a "slave driver." That seems to be an apt description of these men.

The "foremen," however, are Israelites. They are labeled sōterāy', which can also be rendered as "captains," "leaders," or "managers." These are the Hebrews charged with supervising their fellow workers and reporting to the taskmasters. They are still slaves, however, and subject to the same suffering as others (Exodus 5:14–16).

Pharaoh will have specific instructions for both groups (Exodus 5:7–8); this order is intended to be brutally harsh.