ʿAbd Allāh bin ʿUmar [bin al-Khaṭṭāb](may Allāh be pleased with them) who said: I heard the Messenger of Allāh (ﷺ) saying, *"Islām is built upon five (pillars): The testimony that none has the right to be worshipped (in truth) but Allāh and that Muḥammad is the Messenger of Allāh, establishing the (daily) prayer(s), giving the zakāh, pilgrimage to the house and fasting in Ramaḍān."* [Ṣaḥīḥ al-Bukhārī & Muslim] Click here for an overview of the five pillars of Islām: https://www.troid.org/an-introduction-to-the-foundations-of-islam/2/