Gregory of Elvira, on Isa 11:1

“And there shall come forth a rod out of the root of Jesse, and a flower shall rise up out of his root.”

“Just as when a lion is born from a lion, the nature is not changed but is shown to have a common source, so also one who is born from God cannot be anything other than God. But he calls him a lion's cub for the purpose of signifying the Son. Indeed, he adds "from a sprout, my son, you have gone up," because he wants to show us that Christ came from the sprout of Judah, as it was also said through the prophet Isaiah: "there will come forth a rod [virga] out of the root of Jesse, and a flower will go up from his root." This Jesse was the father of David, from whose root, that is, source, the Virgin Mary [maria virgo] was born. That Isaiah refers to a "rod" [virga] and to a "flower" from the rod suggests that the flower which is Christ would be born from a virgin [virgine].”

Imported from an open dataset — not yet checked against the printed edition.