Likutei Sichos – Vol 31 p 028 ff – Pharoah’s Two Stubbornesses are for all 10 makkos

Vaeira

Exile and Redemption (091)

In contrast to the convention that there are two successive stages to the Pharaoh’s stubbornness; one where he is stubborn on his own and another where Hashem makes him stubborn. The Rebbe proves that: 1) The two levels of the Pharaoh’s stubbornness are simultaneous and last for the duration of all ten Makkos beginning with the very first. His first stubbornness makes some sense; while the second makes no sense whatsoever. 2) Moshe was told about these two levels of stubbornness so he could combat it with two levels of קבלת עול to counteract the Klipa.