Sahih al-Bukhari 2638Book 52, Hadith 2
Allah's Messenger (ﷺ) and Ubai bin Ka`b Al-Ansari went to the garden where Ibn Saiyad used to live. When Allah's Messenger (ﷺ) entered (the garden), he (i.e. Allah's Messenger (ﷺ) ) started hiding himself behind the date108 palms as he wanted to hear secretly the talk of Ibn Saiyad before the latter saw him. Ibn Saiyad wrapped with a soft decorated sheet was lying on his bed murmuring. Ibn Saiyad's mother saw the Prophet hiding behind the stems of the date-palms. She addressed Ibn Saiyad saying, "O Saf, this is Muhammad." Hearing that Ibn Saiyad stopped murmuring (or got cautious), the Prophet (ﷺ) said, "If she had left him undisturbed, he would have revealed his reality." (See Hadith No. 290, Vol 4 for details)