Avrumi Hersh asks:
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Why is a kesubas bnin dichrin for sons only, not daughters, rashi says the whole purpose is that a person should give money for his daughters marriage knowing that if she dies b4 her husband, the money will stay in the hands of the grandsons. Why only grandsons not granddaughters?
Avrumi Hersh, London england
The Kollel replies:
The Gemara in Kesuvos 52b asks your question ("Bas Bein ha'Banim..."), and the Gemara answers that Chazal wanted this to be like a regular Yerushah where a daughter does not receive when there are sons (see there for the continuation of the Gemara).
All the best,
Reuven Weiner