إن هي إﻻ أسماء سميتموها أنتم وآباوكم
They are but names which you have named -- you and your fathers, (of your own desire),
ما أنزل الله بها من سلطان
for which Allah has sent down no authority.
meaning, proof,
إن يتبعون إﻻ الظن وما تهوى اﻻنفس
They follow but a guess and that which they themselves desire,
they have no proof, except their trust in their forefathers who took this false path in the past, as well as, their lusts and desires to become leaders, and thereby gain honor and reverence for their forefathers,
ولقد جاءهم من ربهم الهدى
whereas there has surely come to them the guidance from their Lord!
meaning, Allah has sent them Messengers with the clear truth and unequivocal evidence. However, they did not adhere to or follow the guidance that came to them through the Prophets.
Wishful Thinking does not earn One Righteousness
Allah the Exalted said,
أم لﻼنسان ما تمنى