Ibn 'Umar (May Allah be pleased with them) reported:
The Messenger of Allah ﷺ said, "Islam is based on five (pillars): testifying that there is no true god except Allah and that Muhammad ﷺ is His slave and Messenger; performing of Salat (Iqamat-as-Salat), the payment of Zakat; performing Hajj (pilgrimage) to the House [of Allah (Ka'bah)]; and Saum (fasting) during the month of Ramadan."

[Al-Bukhari and Muslim].

وعن ابن عمر رضي الله عنهما قال: قال رسول الله ﷺ: " بني الإسلام على خمس: شهادة أن لا إله إلا الله وأن محمدًا رسول الله، وإقام الصلاة، وإيتاء الزكاة، وحج البيت، وصوم رمضان" ((متفق عليه)).