The coupling of Abba and Imma — root of Zeir Anpin's Mental Powers — is constant; that of Israel Sabba and Tevunah is intermittent.
Abba-Imma coupling is constant. Israel Sabba-Tevunah (their operational sub-couple) coupling is intermittent.
Op. 113 specifies temporal features of the parental couplings. Abba and Imma's main coupling — the source of Z"A's Mental Powers — is constant. The same parents have a sub-couple, Israel Sabba and Tevunah (ISOT), whose coupling is intermittent. The cycle requires both modes.
Constant coupling is what gives the cosmic government its standing root. Z"A's Mental Powers are continuously available because Abba-Imma's coupling never pauses. Without this, Z"A's governance would be intermittent at the structural level — the Mental Powers would fade out periodically, and the cosmic government would lose continuity.
Intermittent coupling is what gives the cosmic government its operational variability. The Israel Sabba-Tevunah couple operates with varying intensity, depending on what the cycle's current phase requires. This intermittency is structurally important — it lets the cosmic government adjust to changing conditions without disrupting the standing root.
The pairing is structurally precise: a constant root plus an intermittent transfer-mechanism. The cycle requires both. Without the constant root, the cosmic government would be unstable; without the intermittent transfer-mechanism, the cosmic government would be inflexible.
Op. 117–118 (additional Partzufim — Jacob and Leah — generated by the operational variability). Op. 128 (the regular oscillation between First and Second Maturity — the rhythmic instance of intermittency).