Markus 4:12

4:12 so that although they look they may look but not see,

and although they hear they may hear but not understand,

so they may not repent and be forgiven.” ¹ 

Markus 5:26

5:26 She had endured a great deal under the care of many doctors and had spent all that she had. Yet instead of getting better, she grew worse.

Markus 12:5

12:5 He sent another, and that one they killed. This happened to many others, some of whom were beaten, others killed.

[4:12]  ¹ sn A quotation from Isa 6:9-10. Thus parables both conceal or reveal depending on whether one is open to hearing what they teach.