The Messenger of Allah ﷺ said, "Islam is built upon five: the testimony that there is no god but Allah and that Muhammad is the Messenger of Allah, the establishment of prayer, the giving of zakat, fasting in Ramadan, and pilgrimage to the House."
حدثنا ابن أبي عمر حدثنا سفيان بن عيينة عن سعير بن الخمس التميمي عن حبيب بن أبي ثابت
قال رسول الله ﷺ بني الإسلام على خمس شهادة أن لا إله إلا الله وأن محمدا رسول الله وإقام الصلاة وإيتاء الزكاة وصوم رمضان وحج البيت
[Sahih]. See the following hadith under the same number. On this topic there is also a report from Jareer bin Abdullah [Ahmad: 4/363, 364]. The hadith of Hanzala bin Abu Sufyan was agreed upon by Bukhari, no. 8, and Muslim, no. 16/22.