The Prophet of Allah ﷺ said, "When a believer desires a child in Paradise, its conception, birth, and growth to maturity will all take place in a single moment, just as he wishes."
حدثنا علي بن عبد الله حدثنا معاذ بن هشام قال حدثني أبي عن عامر الأحول عن أبي الصديق
أن نبي الله ﷺ قال إذا اشتهى المؤمن الولد في الجنة كان حمله ووضعه وسنه في ساعة واحدة كما يشتهي
Its isnad is hasan. Amir Ahwal is Ibn Abdul-Wahid, truthful but with errors, and Abu Siddiq is Naji, Bakr bin Amr, mentioned previously. The hadith is found in Tirmidhi 4/683, no. 2546, where he said, hasan gharib, Ibn Majah 2/1452, no. 4339, and Darimi 2/434, no. 2834.