I took these scriptures from the NIV version of the Holy Bible. You might find more or less scriptures pertaining to mules by using other versions of the Bible.
ll Samuel 13:29
So Absalom's men did to Amnon what Absalom had ordered. Then all the king's sons got up, mounted their mules and fled.
ll Samuel 18: 9-18
Now Absalom happened to meet David's men. He was riding his mule and as the mule went under the thick branches of a large oak, Absalom's head got caught in the tree. He was left hanging in midair, while the mule he was riding kept going on.
l Kings 1:32-34
33he said to them: "Take your lord's servants with you and set Solomon my son on my own mule and take him down to Gihon.
l Kings 1:38
So Zadok the Priest, Nathan the prophet, Benaiah son of Jehoiada, the Kerethites and the Peletites went down and put Solomon on King David's mule and escorted him to Gihon.
l Kings 1:44
The king has sent with him Zakok the priest, Nathan the prophet, Benaiah son of Jehoiada, the Kerethines and the Pelethintes, and they have put him on the king's mule.
l Kings 10:25
"Year after year, everyone who came brought a gift-articles of silver and gold, robes, weapons and spices, and horses and mules.
l Kings 18:5
"Ahab had said to Obadiah, 'Go through the land to all the springs and valleys. Maybe we can find some grass to keep the horse and mules alive so we will not have to kill any of our animals.'"
ll Kings 5:17
"'If you will not,' said Naaman,'please let me, your servant, be given as much earth as a pair of mules can carry, for yoru servant will never again make burnt offerings and sacrifices to any other god but the Lord."
l Chronicles 12:40
"Also, their neighbors from as far away as Issachar, Xebulun and Naphtali came bringing food on donkeys, camels, mules and oxen...."
ll Chronicles 9:24-25
"Year after Year, everyone who came brought a gift-articles of silver and gold, and robes, weapons and spices, and horses and mules. 25Solomon had four thousand stalls for horses and chariots and twelve thousand horses, which he kept in the chariot cities and also with him in Jerusalem."
"They had 736 horses, 245 mules, 435 camels and 6,720 donkeys."
"There were 736 horses, 245 mules...."
"Do not be like the horse or the mule, which have no understanding but must be controlled by bit and bridle or they will not come to you."
"And they will bring all your brothers, from all the nations, to my holy mountain in Jerusalem as an offering to the Lord-on horses, in chariots and wagons, and on mules and camels', says the Lord 'They will bring them, as the Israelites bring their grain offerings, to the temple of the Lord in ceremonially clean vessels.'"
"Men of Beth Togarmah exchanged work horses, war horses and mules for your merchandise."
"A similar plague will strike the horses and mules, the camels and donkeys, and all the animals in those camps."