"And the Nile will swarm with frogs, and they will come up and go into your houses, into your bedrooms and even into your beds. They will go into the houses of your servants and of your people, into your ovens and into your kneading troughs." (Ex. 7:28)

The Sanz-Klausenberger Rebbe taught (in Divrei Torah #677) that a Jew is required to learn from the self-sacrifice of the frogs which came to plague the Egyptians. (Parshat Va'eira) They are an example of how to serve G‑d with self-sacrifice.

The Jewish People…greatly desired to serve G‑d with total self-sacrifice…

When are the kneading troughs found next to the oven? When the oven is hot and the dough is ready to bake. The frogs voluntarily went into the glowing hot ovens even though they were not commanded concerning the sanctification of G‑d's name, nor were they promised any reward for being the agents of the plague. They gave their lives for the sanctification of G‑d's holy name in carrying out the plague. All the more so we, who are commanded to sanctify G‑d's name (through total self-sacrifice), are required to go to any necessary length to ensure the sanctification of G‑d's name in the world.

The Jews in Egypt did actually gain inspiration from the frogs in the concept of self-sacrifice. When they were commanded to take the Passover sacrifice, each family took a sheep and tied it to their bedposts, where it remained for the next five days. The Egyptians saw this they demanded an explanation exclaiming, "What are you doing with our deity tied up on the bedpost!" (Ex. 12:1-6)

The Jewish People could have answered that they were going to treat the sheep like pets, drinking their milk and shearing their wool, but they greatly desired to serve G‑d with total self-sacrifice. Instead they told the truth, at great risk of their lives. They told the Egyptians that they intended to slaughter the animal as a sacrifice to the Hebrew G‑d. The Egyptians could only gnash their teeth in frustration; powerless to respond. (Tur Orach Chaim 430 in the name of the Seder HaOlam) How then was it permitted for them to challenge the Egyptians and risk their lives?

The decisiveness of the Jewish Nation is really quite amazing because at that time they were entrenched in 49 levels of spiritual impurity and almost on the verge of spiritual annihilation. In fact, they were still dabbling in idol worship. (see Ex. 12:6,21) Normally, only a person of exceptional stature is allowed by Jewish Law to give his life to sanctify G‑d's name. An ordinary Jew is required to demonstrate self sacrifice only for the three cardinal transgressions; idol worship, forbidden sexual relationships and murder. And at that time, it might have even been questionable if the Jewish People were on that level. How then was it permitted for them to challenge the Egyptians and risk their lives to sanctify G‑d's name?

Rabbi Moshe Teitlebaum of Uhely (Yismach Moshe, Ki Tisa, p.188) writes that perhaps it is because they began keeping the Shabbat in Egypt. (See Tur Orach Chaim 281) Our sages have said that one who keeps Shabbat according to all its laws is forgiven from any transgressions, even if he served idols as heartily and enthusiastically as the generation of Enosh. (Shabbat 118b) Furthermore, in the place where baalei teshuva [penitents] stand, even perfect tzadikim are not granted admission. (Shabbat 34b) Therefore, at that critical moment, the Israelites were elevated by the mitzvah of Shabbat. They were thus permitted to carry out the mitzvah of taking the Pascal Lamb, at great personal risk, and thereby affected a resounding sanctification of G‑d's name.

[Source: www.nishmas.org