Ibn 'Umar (May Allah be pleased with them) reported:
The Messenger of Allah ﷺ said, "(The superstructure of) Islam is based on five (pillars), testifying the fact that La ilaha illallah wa anna Muhammad-ar-Rasul-ullah [there is no true god except Allah, and Muhammad ﷺ is the Messenger of Allah], establishing As- Salat (the prayers), paying Zakat (poor due), the pilgrimage to the House [of Allah (Ka'bah)], and the Saum (fasting) during the month of Ramadan."

[Al-Bukhari and Muslim].

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