Sahih al-Bukhari 26

Narrated Abu Huraira:

Allah’s Messenger (ﷺ) was asked, “What is the best deed?” He replied, “To
believe in Allah and His Apostle (Muhammad). The questioner then
asked, “What is the next (in goodness)? He replied, “To participate in
Jihad (religious fighting) in Allah’s Cause.” The questioner again
asked, “What is the next (in goodness)?” He replied, “To perform Hajj
(Pilgrim age to Mecca) ‘Mubrur, (which is accepted by Allah and is
performed with the intention of seeking Allah’s pleasure only and not
to show off and without committing a sin and in accordance with the
traditions of the Prophet).”