Song of Solomon 1:9 (ESV)

9 I compare you, my love, to a mare among Pharaoh’s chariots.

The husband told his wife where she could find him at noon. Before he left with the flock, he said she was the most beautiful among women. Now he elaborates some more on this. He sings of her beauty in Song of Solomon 1:9–11. He does so in a way that may seem rather strange to us today. Yet even loved ones among us use phrases that take on a very special meaning. For example, one calls the other darling or sweetheart. Lovers can have very confidential terms of endearment for each other that express their special love for each other.

The husband here compares his wife to a mare. He compares her to a horse selected by Pharaoh to pull the royal chariots. That is the job of the finest horses. Only the best are picked for this.