Qailah bint Makhramah (May Allah be pleased with her) reported:
I saw the Prophet (ﷺ) seated with his arms enfolding his legs; and when I saw him in such a state of humble guise I trembled with fear due to the awe (he showed in that posture).[At-Tirmidhi]. (ES)
App reference (ES): Book 5, Hadith 10 (ES)
Arabic/English book reference (ES): Book 5, Hadith 823 (ES)