I've been currently reading some of our blessed scholars such as Ayatullah Khomenei RH and Allamah Tabatabai RH and they are of the opinion that the universe is eternal and have given various philosophical arguments for this view, my question is does this belief in the eternity of the universe constitute kufr (ie go against the teachings of the ahlulbayt) from my limited understanding of the argument proposed by these scholars on an aqli basis I heavily lean on this view but I am not sure if I should affirm it or not.

Scholars have different views on this matter. Historically, most scholars have rejected this view (some of it is soft rejection while some of it is hard rejection coupled with accusations of kufr for one who believes in that).

Majority of scholars today still reject this belief.

They have cited some hadiths such as:

إن الله تبارك وتعالى كان ولا شئ غيره


لا إله إلا أنت، كنت إذ لم تكن سماء مبنية، ولا أرض مدحية، ولا شمس مضيئة، ولا ليل مظلم، ولا نهار مضئ، ولا بحر لجي، ولا جبل رأس، ولا نجم سار… كنت قبل كل شئ، وكونت كل شئ، وقدرت على كل شئ، وابتدعت كل شئ

And you can find hadiths here that indicate the universe is not eternal: