Is it forbidden to think about the form of Allah and to imagine strange forms for Him?

Falling into this problem is due to two matters:

First: The corrupt notion of likening the Creator to the created. Allah has nullified this notion with His saying: {There is nothing like unto Him, and He is the All-Hearer, the All-Seer} and His saying: {Say, "He is Allah, [who is] One, Allah, the Eternal Refuge. He neither begets nor is born, Nor is there to Him any equivalent."} Its remedy: Believing that the Creator is far removed from resembling His creations, {and they do not encompass Him in knowledge}.

Second: Indulging in the whispers of Satan. When Satan fails to turn a person away from the worship of Allah, he tries to drag him into contemplating the essence of Allah Almighty. Its remedy: Turning away from these whispers and seeking refuge with Allah from the accursed Satan, as the Prophet, peace and blessings be upon him, guided: "Satan comes to one of you and says: 'Who created such and such?' until he says to him: 'Who created your Lord?' So when he reaches that, let him seek refuge with Allah and stop."

What is obligatory upon you, when these whispers occur, is to turn away from them, repel them, and seek help from Allah.