Hadith 1352B4

قَالَ مَالِك : مَنْ سَلَّفَ فِي حِنْطَةٍ شَامِيَّةٍ، فَلَا بَأْسَ أَنْ يَأْخُذَ مَحْمُولَةً بَعْدَ مَحِلِّ الْأَجَلِ .
Imam Malik, may Allah have mercy on him, said that if a person stipulates fine wheat in a salam contract, then after the term has passed, he takes better or worse wheat than that, there is no harm in it provided that the weight is the same as was stipulated. The same ruling applies to grapes and dates.
Hadith Reference موطا امام مالك رواية يحييٰ / كتاب البيوع / 1352B4
Hadith Takhrij «فواد عبدالباقي نمبر: 31 - كِتَابُ الْبُيُوعِ-ح: 49»