From Sahih Bukhari (Hadith 527):
Narrated `Abdullah:I asked the Prophet (ﷺ) "Which deed is the dearest to Allah?" He replied, "To offer the prayers at their early stated fixed times." I asked, "What is the next (in goodness)?" He replied, "To be good and dutiful to your parents" I again asked, "What is the next (in goodness)?" He replied, 'To participate in Jihad (religious fighting) in Allah's cause." `Abdullah added, "I asked only that much and if I had asked more, the Prophet (ﷺ) would have told me more
Reference: Bukhari 527