There are two positive mitzvos in the Torah that share certain qualities. Aside from being "Mitzvot Asei," both of them are the only mitzvos in the Torah for which if one does not fulfill them, the person’s soul is subject to kareis - a repercussion which has a number of possible definitions, but minimally could mean to be “cut off” from an eternal connection to God (whatever that might mean). Both of them have blood associated with the fulfillment of the mitzvah. Both of them require preparation in advance. One of them cannot be fulfilled without the other one having been fulfilled. (list is not exhaustive)
The two mitzvos? Bris Milah (circumcision) and Korban Pesach (the Paschal Lamb). It is noted that absent a Beis HaMikdash we don’t fulfill the Korban Pesach, so some of the connections are less relevant in our time.
Rashi (12:6) quotes verses from Yechezkel 16 which describe metaphorically God’s turning Jerusalem into a presentable city, including stating “And I passed by you and saw you downtrodden with your blood, and I said to you, 'With your bloods, live,' and I said to you, 'With your bloods, live.'” Many Midrashim say the plural form of ‘bloods’ indicates that blood of the Paschal lamb and circumcision blood were combined and placed on the doorposts in Egypt to serve as a double protection for the Hebrews during the final plague.
