On Yom Kippur there are 5 prohibitions
No Leather Shoes
That are against the 5 prayers we pray on Kippur and against 5 types of judgements the 5 fingers and against 5 letters of מנצפך and against the court of 5 (that were left from previous worlds).
After we were judged on Rosh Hashanah, its as if we have received a check of say $1,000,000 - one that was written but not signed.
On Yom Kippur during the Neilah נעילה we pray for the first signature and this is why on Rosh Hashanah we say Inscribe us in the book of life, but at the end of the Neilah נעילה we say seal us (give us the first signature). IMA is the one that signs the first signature with the 5 fingers in the womb that's called רחם which alludes to mercy.
Another reason we want this first seal is that the Evil Forces cannot act on the judgments lest they are not in our favor, we want to delay the execution until the second seal that is done on HOSHANA RABBA in which time we go out and check our SHADOW at midnight against the moon. If a limb is missing, it is a sign of unfavorable judgment and we have time to repent until the MUSSAF prayer of Shmini Atzert up to the reciting of the KEDUSHA - once we say SHEMA YISRAEL the judgements go out for execution. The 2 seals guarantee that the Evil Forces do not come and erase the digit 1 (of 1,000,000) so as not to live us with 000,000.
IMA is the one that signs the decrees because Yom Kippur is about IMA that affords us rectification and repentance. Also IMA has the capacity to smack the Evil forces while ABA can expel them and sefira KETER to nullify destroy them like it was done at Mount Sinai.
The seal of IMA is קסא קמג קנא adding up to 455 = מיתה meaning DEATH that we seek to cancel and therefore give us LIFE.