Here is a question:
Why was is specifically Hillel HaZaken who instituted Korech (eating the matzah and marror together)?
R’ Shlomo Kluger zt”l states that we can derive the answer from a story we see in the gemarra in brachos.
Hillel HaZaken was traveling home when he heard a piercing, wailing cry. Hillel HaZaken immediately stated that it was not coming from his home. There is a passuk written about him: ?????? ??????, ??????? ????’ ??????? ??????, ??? ?????? his heart is stedfast, trusting in the Hashem, His heart is established, he shall not be afraid (okay, so parts of 2 pesukim)
Why was Hillel HaZaken so sure it wasn’t from his home? We see that Yaakov Avinu was afraid of Eisav (because of the sin of Yaakov), we also see that Moshe was afraid of Og (because he had zechusim). So how could Hillel HaZaken be so sure?
Rather, Hillel HaZaken knew the scream wasn’t coming from his home because every member of his home would say “gam ze l’tova” and accept what ever it was with ahava. Thus no member of his home would give such a scream, so the scream must be from elsewhere.
We know that the maror represents the enslavement and the tzaros while the matzah represents the geula and tova. Since we know that Hillel accepted and blessed the bad no differently then he would the good and he believed that all that happens is for the good. Therefore he ate the matza and maror (the good and the bad) together!