Arcana Coelestia # 3285
3285. 'Isaac prayed to Jehovah' means communication of the Divine which is the Son with the Divine which is the Father. This is clear from the meaning of 'praying' as communicating, for prayer is nothing other than communication, and from the representation of 'Isaac' as the Divine Rational. The Divine which is the Son is 'Isaac' - that is, the Rational when truth had been joined to it - whereas the Divine which is the Father is 'Jehovah' here. This communication took place in the Lord, for 'the Father was in the Son, and the Son in the Father', John 14:10-11.
John 14:10-11
10
Don't you believe that I am in the Father, and the Father in me? The words that I tell you, I speak not from myself; but the Father who lives in me does his works.
11
Believe me that I am in the Father, and the Father in me; or else Believe me for the very works' sake.
