Mark 9:13

9:13 But I tell you that Elijah has certainly come, and they did to him whatever they wanted, just as it is written about him.”

Mark 10:5

10:5 But Jesus said to them, “He wrote this commandment for you because of your hard hearts. ¹ 

[10:5]  ¹ tn Grk “heart” (a collective singular).