السلام عليكم ورحمة الله وبركاته حياكم الله If someone do not know the Tashahhud properly by heart, is it permissible for him to read it from the phone or from a piece of paper during the prayer until he memorized it? How should a person do it in the best way? BarakAllahu feekum, ustadh.

Ustadh AbdulAziz al-Haqqan

Yes