Sayyiduna Jabir (may Allah be pleased with him) said: A boy was born to a man among us, and he named him al-Qasim. We said: We will not call you by the kunyah Abu al-Qasim. This was mentioned to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Name your son Abd al-Rahman."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19321