Sahih Bukhari
Companions of the Prophet
Volume: 005 / Book Number: 057 / Hadith Number: 80
Narrated 'Abdullah bin Dinar:
One day Ibn 'Umar, while in the Mosque, looked at a man who was dragging his clothes while walking in one of the corners of the Mosque He said, "See who is that. I wish he was near to me." Somebody then said (to Ibn 'Umar), "Don't you know him, O Abu 'Abdur-Rahman? He is Muhammad bin Usama." On that Ibn 'Umar bowed his head and dug the earth with his hands and then, said, "If Allah's Apostle saw him, he would have loved him."