Aqra bin Habis asked the Prophet ﷺ, "Messenger of Allah, is the Hajj to be performed every year, or only once?"He replied, "Only once. Whoever is able to do more, it is voluntary."
حدثنا يعقوب بن إبراهيم الدورقي حدثنا يزيد بن هارون أنبأنا سفيان بن حسين عن الزهري عن أبي سنان
أن الأقرع بن حابس سأل النبي ﷺ فقال يا رسول الله الحج في كل سنة أو مرة واحدة قال بل مرة واحدة فمن استطاع فتطوع
[Sahih] Abu Dawud, in the book of rituals, chapter on the obligation of Hajj, hadith 1721, from the hadith of Yazid, with Sufyan bin Husayn transmitting it, corroborated by Muhammad bin Abu Hafsa, Abdul-Jalil bin Humayd, and others. Zuhri narrated it using the ambiguous "an" form, as mentioned previously, hadith 707. The hadith has many corroborating narrations, see the two preceding hadiths.