If you do not know long Surahs you should not perform Tahajjud Salaat?

Tahajjud Salaat requires one to remain on Salaat (especially standing position) for a long time, reciting long Surahs.

Answer:

One may perform Tahajjud Salaat even if one does not know long Surahs.

and Allah Ta’ala Knows Best
Mufti Ebrahim Desai

Original Source Link

This answer was collected from Askimam.org, which is operated under the supervision of Mufti Ebrahim Desai from South Africa.

Link