Transfer of man's deeds to the World of Reward through Daat of Atik Yomin.
Daat of Atik is the operational anatomy through which man's deeds transfer to the World of Reward.
Op. 99 specifies where in Atik's anatomy the elevation Op. 98 named happens. Daat of Atik — the bridging mental power at the Atik level — is the structural locus of the transfer.
Daat (Knowledge) is the bridging Mochin (Op. 124 will treat Daat in Zeir Anpin (Z"A) explicitly). At every Partzuf level, Daat operates as the structural-functional bridge. Daat of Atik is the bridging Mochin at the Atik level; it is what connects what is happening operationally below to what is registered concealed-cosmically above.
When man performs a deed of service, the deed is — at the operational-temporal level. Daat of Atik picks up the deed and transfers it to the cosmic register where the World of Reward accumulates the deed's value. The transfer is structural; without Daat of Atik, the operational deed and the concealed register would have no connection.
Op. 124 (Daat as the offspring of Abba-Imma engrafting via Chochmah and Binah) — the operational Daat doctrine. Op. 99's Daat of Atik is the upstream structural anchor; Op. 124 is the downstream operational form.