Sahih Al Bukhari (630)

عن عبد الله بن عمر رضي الله عنهما يقول "انطلق رسول الله (صلى الله عليه وسلم) وأبي بن كعب الأنصاري يؤمان النخل التي فيها ابن صياد حتى إذا دخل رسول الله (صلى الله عليه وسلم) طفق رسول الله (صلى الله عليه وسلم) يتقي بجذوع النخل وهو يختل أن يسمع من ابن صياد شيئا قبل أن يراه وابن صياد مضطجع على فراشه في قطيفة له فيها رمرمة أو زمزمة فرأت أم ابن صياد النبي (صلى الله عليه وسلم) وهو يتقي بجذوع النخل فقالت لابن صياد أي صاف هذا محمد فتناهى ابن صياد قال رسول الله (صلى الله عليه وسلم) لو تركته بين"

`Abdullah ibn `Umar (may Allah be pleased with him) narrated: Allah's Messenger (peace be upon him) and Ubay ibn Ka`b Al Ansari went to the garden where Ibn Sayyad used to live. When Allah's Messenger (peace be upon him) entered (the garden), he (i.e. Allah's Messenger (peace be upon him)) started hiding himself behind the date-palms as he wanted to hear secretly the talk of Ibn Sayyad before the latter saw him. Ibn Sayyad wrapped with a soft decorated sheet was lying on his bed murmuring. Ibn Sayyad's mother saw the Prophet (peace be upon him) hiding behind the stems of the date-palms. She addressed Ibn Sayyad saying: "O Saf, this is Muhammad." Hearing that Ibn Sayyad stopped murmuring (or got cautious), the Prophet (peace be upon him) said: "If she had left him undisturbed, he would have revealed his reality."