The following is a map between Isaiah 31 and Song of Solomon. The key matches are Pharaoh's Chariots, Lions and Fire of Yahvah. Question marks signify unknown matches.
13 Isaiah 31:1-3
1Woe to those who go down to Egypt for help and trust in horses and rely on chariots because they are many, and in horsemen, because they are very strong; but they do not trust in the Holy One of Israel, nor seek Yahvah.
2Yet in his wisdom, he will bring a calamity, and will not alter his words; but will arise against the house of evildoers and against the help of those who work iniquity.
3Now the Egyptians are men and not God; and their horses are flesh and not spirit. When Yahvah will stretch out his hand, both the helper will be overthrown, and he that is helped will fall down, and they all will be annihilated together.
31 Song of Solomon 1:9
9I have compared you, my beloved, to a mare in Pharaoh's chariot.
13 Isaiah 31:4
4For thus has Yahvah spoken to me: As the lion, even the young lion, roars over his prey when a multitude of shepherds shout against him, is not afraid of their voice nor terrified by their multitude; so will Yahvah of hosts come down to fight for mount Zion and for its hill.
31 Song of Solomon 4:8
8Come with me from Lebanon, my sister, my bride. Come with me from Lebanon; you will pass over the top of Amana, from the top of Shenir and Hermon, from the lions' dens, from the mountains of leopards.
13 Isaiah 31:5
5As birds flying, so will Yahvah of hosts alight on Jerusalem; he will alight to deliver, rescue, and help.
13 Isaiah 31:7
7For in that day, every man will despise the idols of gold and the idols of silver which your own hands have made for yourselves for a sin.
31 Song of Solomon 5:14-15
14His hands are like golden belts studded with precious stones; his belly is like a work of ivory overlaid with sapphires.
15His legs are like pillars of marble set on bases of gold; his chest is like Lebanon, excellent as the cedars.
*I'm not sure this match is correct.
13 Isaiah 31:8-9
8Then the Assyrian will fall with the sword, not with the sword of men; the sword of mighty men will not devour him; but he will flee from the sword, and his young men will be vanquished.
9And he will live in his rocky habitation, and his princes will be defeated from before the standard, says Yahvah, whose fire is in Zion and his furnace in Jerusalem.
31 Song of Solomon 8:6-7
6Set me as a seal on your heart, as a seal on your arm; for love is strong, as death; desire is cruel, as the grave; its flashes are flashes of fire and flame.
7Many waters cannot quench love, nor can the rivers carry it away; yet if a man would give all the substance of his house for love, people would mock him.
*The last phrase in Song of Solomon 8:6, in the ASV, reads "a very flame of Jehovah." The KJV reads "a most vehement flame." Given the match to Isaiah 31:9, it seems the ASV is the better translation here.