Moses
Genesis 15:9ESV·traditional attribution

He said to him, “Bring me a heifer three years old, a female goat three years old, a ram three years old, a turtledove, and a young pigeon.”

John Calvin Reformed @genevareformer

9. Take me an heifer of three years old . Some, instead of an heifer of three years old translate the passage, ‘three heifers’ and in each species of animals enumerated, would make the number three. Yet the opinion of those who apply the word three to the age of the heifer, is more general.

Matthew Henry Presbyterian @wholebiblehenry

We have here the assurance given to Abram of the land of Canaan for an inheritance. I. God declares his purpose concerning it, Gen 15:7. Observe here, Abram made no complaint in this matter, as he had done for the want of a child. Note, Those that are sure of an interest in the promised seed will see no reason to doubt of a title to the promised land.

Commenting on Genesis 15:7-11

John Gill Reformed Baptist @doctorgill

And he took unto him all these,.... The heifer, goat, ram, turtle, and young pigeon, not to himself, but to the Lord, as he was bid, and offered them before him, as the above Targums paraphrase it; or however he took them for his use, and set them before him, and did with them as he directed him: and divided them in the midst; that...