The substitution of an aleph א for the chet ח in Abel חבל creates a pun in the riddle.  

<ref> {{bgw| Ge 4:10 }} ''And he said, What hast thou done? the voice of thy brother’s blood crieth unto me from the ground.'' [{blood: Heb. bloods }] </ref>}}

Abel  הנל was appropriately named: become '''vain''', '''empty''', breath, Abel. His life became vain when Cain slew him. <ref>{{bgw|Ge 4:8}} ¶  And Cain talked with Abel his brother: and it came to pass, when they were in the field, that Cain rose up against Abel his brother, and slew him.</ref>  

Abel, spelled differently אבל, and so it is a pun, means 'meadow, plain, mourning, nevertheless, verily '.  Compare:

* the voice of thy brother’s blood דמי crieth צעקים unto me from the ground האדמה

* the voice of thy brothers's heart ( הבל the ה heart בל ) mourns הבל unto me from the plain or meadow הבל.  

Ideas are expressed using different words: blood vs. heart, cry vs mourn, ground vs. plain, but the parallels of thought are connected.

 

We also can't miss that now that Abel is 'in the ground' the man 'adam' אדמ is in the ground 'hadamah' האדמה or ה-אדמ-ה.