ﷺ
Sayyiduna Qasim (may Allah be pleased with him) was the eldest of the blessed children and the first to pass away. The blessed Kunyah of the Holy Prophet (peace and blessings be upon him), Abul Qasim, is derived from his name. When Sayyidatuna Khadija (may Allah be pleased with her) expressed grief over his passing before the end of the nursing period, the Holy Prophet (peace and blessings be upon him) said: 'His breastfeeding will be completed in Paradise.'
The Beloved Children of the Prophet (peace and blessings be upon him) · 100 · Maktaba-tul-Madinah
Awaiting scholar review