"The spiritual sense may be defined as the meaning derived from the biblical text when 'read under the influence of the Holy Spirit,' in the context of the Paschal Mystery of Christ and of the new life which flows from it" according to the Pontifical Biblical Commission document,
"Interpreting the Bible in the Church" (1994). It is the passion, death and resurrection of Christ which provides a fresh context in which the ancient biblical texts can be seen as fulfillment and consummation in Christ. As Pius XII observed:
For God alone could have known this spiritual meaning
and have revealed it to us. Now our Divine Savior points out to us and teaches
us this same sense in the Holy Gospel; the Apostles also, following the example
of the Master, profess it in their spoken and written words; the unchanging
tradition of the Church approves it; and finally the most ancient usage of the
liturgy proclaims it . . .
One example given by the Pontifical Biblical Commission (PBC) was the covenant oath which established David's throne forever, which the New Testament revealed is fulfilled in Jesus Christ. The PBC speaks of the new context as "life in the Spirit."
Old Testament texts that relate directly to the pashcal mystery of Christ may have a spiritual sense as their literal sense. This is frequently the case in the New Testament. Hence there isn't always a distinction between the two senses.
On the other hand, John 19: 33-36 records that the two soldiers did not break the legs of our Lord on the Cross because he was already dead and says that this was so that the Scriptures would be fulfilled, referring to Exodus 12: 46. However, this latter passage refers to the Passover of the lamb that God required the Israelites to celebrate annually. It is only when we reflect on the Exodus passage in light of the paschal mystery that we see the spiritual sense emerge according to Fr. Bernard Orchard.
What is important here is that the principle of coming to know and see the spiritual sense of Scripture, which was rejected by the "reformers" during the Reformation, was annunciated by Vatican II as a "revival of the great patristic tradition" (Dei Verbum 12c). Perhaps we should
remember the injunction of St. Jerome, "Whoever interprets the gospel in a spirit and mentality other than those in which it was written disturbs believers and perverts the gospel of Christ . . ." (quoted by Pope Leo XII in Providentissimus Deus 5).