Al-Kāfi - Volume 4 > The Case of One Who Performs al-Hajj on Behalf of Someone but Has Done So on Behalf of another Person
Hadith #2

2ـ مُحَمَّدُ بْنُ يَحْيَى رَفَعَهُ قَالَ سُئِلَ أَبُو عَبْدِ الله (عَلَيْهِ السَّلاَم) عَنْ رَجُلٍ أَعْطَى رَجُلاً مَالاً يَحُجُّ عَنْهُ فَحَجَّ عَنْ نَفْسِهِ فَقَالَ هِيَ عَنْ صَاحِبِ الْمَالِ.

2. Muhammad ibn Yahya in a marfu‘ manner has narrated the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, was once asked about a man who receives a certain amount to perform al-Hajj for another person, but he performs al-Hajj for himself. He (the Imam) said, ‘It is for the owner of the asset.’”