For those who aren’t too astute, the title to this post and the last are meant to be puns. Tertullian’s reading of the Old Testament was certainly typological, and Christological (which isn’t technically ‘literal’), but his constant reference to the “wood” or “tree” (i.e., the cross) which represented the passion of Christ is what I’d like to call “lignocentric.” Tertullian sees the “wood” as the center of Christ’s suffering and sacrifice. It is the “wood” that typifies our covenant with God and salvation in Christ.
Returning to Tertullian’s reading of the Akedah, he says:
This “wood,” again, Isaac the son of Abraham personally carried for his own sacrifice, when God had enjoined that he should be made a victim to Himself. But, because these had been mysteries (Lat. Sacramenta) which were being kept for perfect fulfilment in the times of Christ, Isaac, on the one hand, with his “wood,” was reserved, the ram being offered which was caught by the horns in the bramble; Christ, on the other hand, in His times, carried His “wood” on His own shoulders, adhering to the horns of the cross, with a thorny crown encircling His head.
In Tertullian’s reading, the proper object of sacrifice was never Isaac. The binding was merely a shadow of the sacrament which would be perfectly fulfilled in Christ’s death. This is why the ram was provided to spare Isaac’s life. Christ had no last minute substitute to take his place. His death was the pinnacle of all the prophets had spoken.
To take Tertullian’s thought a bit further, I’d note how Christ’s death (on the “wood”) stands at the center of the two universally agreed upon sacraments in Christendom, i.e., the Eucharist (Lord’s Supper) and Baptism. In the Eucharist we give thanks for and meditate upon the eternal sacrifice of the spotless Son. It is the remembrance of the shedding of his blood for the remission of our sins, and the remembrance of the breaking of his body which was done for us so that we may be made whole. Baptism is the believer’s identification with Christ in death and resurrection. If we don’t aren’t first crucified with Christ then we have no reason to be symbolically buried and resurrected in baptism. We must first die to self before we can rise to the newness of life in Christ.
B”H
Rightly Dividing the Word of Truth 
In Leviticus 14:4, the leper is cleansed by the hyssop, blood and cedar wood. Does Tertullian related this wood to the cross also?
Suzanne: Surprisingly, no. He makes very little reference at all to Leviticus 14 as far as I can tell, which is interesting since the passage you mention seems like a prime candidate for mention in the section I have been quoting from.