Allah's Messenger (ﷺ) said, "Shall I inform you of the biggest of the great sins?" They said, "Yes, O Allah's Apostle!" He said, "To join partners in worship with Allah, and to be undutiful to one's parents. "
Sahih al-Bukhari Book 79, Hadith 47
← Previous Hadith I saw Allah's Messenger (ﷺ) in the courtyard of the Ka`ba in the Ihtiba.' posture putting his hand round his legs like this.

Sahih al-Bukhari Book 79, Hadith 46 Next Hadith → as above (No. 290) adding: The Prophet (ﷺ) was reclining (leaning) and then he sat up saying, "And I warn you against giving a false statement." And he kept on saying that warning so much so that we said, "Would that he had stopped."

Sahih al-Bukhari Book 79, Hadith 48