They found their fathers in error, so they rush after their footsteps
إنهم ألفوا آبائهم ضالين فهم على آثارهم يهرعون
They, meaning these wrongdoers who are being punished with this punishment, found, meaning discovered, their fathers. The word "found" (alafa) means discovered, and from this is His saying, the Exalted:
and they found her husband at the door
وألفيا سيدها لدا الباب [Yusuf 12:25]
The word "found" (alafa) in her statement is like this, and from it, meaning discovered, her statement. So the meaning of
They found their fathers
ألفوا آباءهم
is that they found them in error, lost from the truth. He says:
So they rush after their footsteps
فهم على آثارهم يهرعون
They found their fathers in error after the proof had become established against them regarding the error of their fathers. But did they follow the proof? No. He says: "So they," meaning after they found their fathers in error, and may Allah protect us from that, they
They rush after their footsteps
على آثارهم يهرعون
are driven and hurried. "Hara'a" means to hasten and speed up in something. So they rush after the footsteps of their fathers and after what they were upon of shirk (associating partners with Allah) and oppression. They rush, meaning they are driven with intensity and hasten to follow in their footsteps. And the messengers came to them with the truth, but how did they answer? They said:
Indeed, we found our fathers upon a religion, and we are in their footsteps [rightly] guided."
إنا وجدنا آباءنا على أمة وإنا على آثارهم مقتدون [Az-Zukhruf 43:22]
And in the other verse:
And we are following in their footsteps
وإنا على آثارهم مهتدون
meaning, and we do not accept this. So they knew that their fathers were in error, and yet, and may Allah protect us from that, they remained upon what they were upon. Rather, they became racing and clinging more tightly to what their fathers were upon. So they rush after their footsteps, meaning they are hurried to follow them, so they hasten to it. The entire speech is about the polytheists of Quraysh, as evidenced by his saying: