Can you use Hidden Blade on a unit with Temporary during the Beginning Phase, by putting Hidden Blade on the chain in response to the Temporary trigger?

Ruling: Yes, you can use Hidden Blade on a unit with Temporary during the Beginning Phase by responding to the Temporary trigger.

Sequence:

• Beginning Phase: Temporary triggers (chain 1)
• Reaction: Hidden Blade activates on that Temporary unit, killing it and drawing 2 cards

Nuances:

• The unit must still be on the battlefield where the Hidden Blade was hidden