Musannaf Ibn Abi Shayba 18:481

Abu Bakr narrated to us, he said: Isma'il bin 'Ayyash narrated to us, from 'Ubaydullah bin 'Umar, from Ayyub bin Musa, from 'Ata', Makhul, and Ibn Shihab, who said: Its value is on the day it is struck, no matter how much it reaches.