6th Day Chol HaMoed Sukkot
Erev Chag Shemini Atzeret
For [the] seven days [of Sukkot] you shall bring a fire offering to G‑d. On the eighth day, it shall be a holy convocation for you... It is a [day of] detention.
[G‑d says to Israel,] "I have detained you [to remain] with Me." This is analogous to a king who invited his sons to feast with him for a certain number of days, and when the time came for them to leave, he said: "My sons! Please, stay with me just one more day; it is difficult for me to part with you!"
—Rashi's commentary ad loc (Source)
Abba Sheb'Shamayim, draw your children close to you, console us and comfort us with Your love and mercy and send us our righteous Mashiach without any further delays!
~Chag Shemini Atzeret Sameach~