Sa'id bin Jubayr (may Allah have mercy on him) says that a man passed by Ibn Abbas (may Allah be pleased with them both) reciting the talbiyah for Hajj on behalf of Shubrumah. He asked: Who is Shubrumah? He said: He made a bequest that Hajj be performed on his behalf. He asked: Have you performed Hajj for yourself? He said: No. Ibn Abbas (may Allah be pleased with them both) said: First perform Hajj for yourself, then perform it on behalf of Shubrumah.
(b) Ata (may Allah have mercy on him) says that a man may perform Hajj on behalf of his father even if he did not make a bequest.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9854