“Moses called all the elders of Israel and said to them: ‘Draw forth and take for yourselves sheep for your families, and slaughter the Paschal lamb.’” (Shemot 12:21)
Our Sages taught (Shemot Rabbah 15:2): “‘Draw forth’ — withdraw your hands from idolatry, and ‘take’ sheep for the Pesach offering.”
This requires explanation. How could it suffice merely to “withdraw one’s hands” from idolatry to deserve salvation? One who has served idolatry surely requires full repentance and a complete abandonment of his evil path, as the verse states: “Let the wicked abandon his way ... and return to Hashem, and He will have mercy upon him” (Yeshayah 55:7). How, then, could the Sages say that this simple withdrawal was enough?
It may be explained that, without question, the Children of Israel truly desired to be faithful to HaKadosh Baruch Hu. However, because of the mental confusion and the crushing oppression they endured in Egypt, their inclination overcame them and led them to behave like the Egyptians, as is described in the Midrashim. Therefore, the verse specifies: “Draw forth and take for yourselves” — that is, withdraw your hands from idolatry, for they served it only under coercion. Consequently, it was sufficient for them to express their will to separate from idolatry and to offer a sacrifice to HaKadosh Baruch Hu.
This accords with what Rambam writes in the laws of divorce (Hilchot Gerushin 2:20) regarding a man who is obligated to divorce his wife but refuses to do so. The Beit Din compels him until he says, “I want [to divorce],” and then the bill of divorce is valid. At first glance, this is puzzling: how can a divorce be valid if the husband was forced to say “I want”? Rambam explains that, in truth, such a person desires to be part of Israel, to fulfill the commandments, and to distance himself from transgressions; it is only that, at that moment, his Evil Inclination overpowered him and prevented him from fulfilling this mitzvah. When, through coercion, his Evil Inclination is weakened and he says “I want,” he is in fact acting in accordance with his true and deepest will.
So too with the Children of Israel in Egypt. The Egyptians forced them to commit transgressions and to serve idolatry, but their inner and genuine desire was directed toward the Holy One, blessed be He. Therefore, as soon as they withdrew their hands from idolatry—that is, once the coercion ceased and they said, “We want [to abandon idolatry and serve Hashem alone]” — their authentic will to fulfill the will of their Creator was revealed. In truth, even beforehand their hearts were with Hashem; they were merely subjugated by the power of Egypt.
(Zera Shimshon, Parashat Bo, art. 10)