Al-Kāfi - Volume 5 > Advance Payment for Buying Slaves and Animals
Hadith #6

6- أَحْمَدُ بْنُ مُحَمَّدٍ عَنْ عَلِيِّ بْنِ الْحَكَمِ عَنْ قُتَيْبَةَ الأعْشَى عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) فِي الرَّجُلِ يُسْلِمُ فِي أَسْنَانٍ مِنَ الْغَنَمِ مَعْلُومَةٍ إِلَى أَجَلٍ مَعْلُومٍ فَيُعْطِي الرَّبَاعَ مَكَانَ الثَّنِيِّ فَقَالَ أَلَيْسَ يُسْلِمُ فِي أَسْنَانٍ مَعْلُومَةٍ إِلَى أَجَلٍ مَعْلُومٍ قُلْتُ بَلَى قَالَ لا بَأْسَ.

6. Ahmad ibn Muhammad from has narrated from Ali ibn al-Hakam from Qutaybah al-‘A’sha’ who has said the following: “About the case of a man who makes advance payment for sheep of a certain age for an appointed time and the party gives him four years old in place of three years old, abu ‘Abd Allah, ‘Alayhi al- Salam, asked, ‘Is it not true that he has made advance payment for (animals of) known age and on an appointed time? I replied, ‘Yes, that is true.’ He (the Imam) said, ‘It is not unlawful.’”