Musannaf Ibn Abi Shayba 13:1342

Abu Bakr narrated to us, he said: Humayd ibn Abd al-Rahman narrated to us, from Hasan ibn Salih, from Mutarrif, from Shurayh, regarding a house that is purchased while there is an absent pre-emptor (shafi') or a minor one. He said: The absent one has more right to the pre-emption until he returns, and the minor until he reaches maturity.