Good Manners and Form (Al-Adab)
Bukhari :: Book 8 :: Volume 73 :: Hadith 208
Narrated Jabir bin 'Abdullah:
A man among us begot a boy whom he named Al-Qasim. The people said (to him), "We will not call you Abul-l-Qasim, nor will we please you by calling you so." The man came to the Prophet and mentioned that to him. The Prophet said to him, "Name your son 'Abdur-Rahman."