(36) باب اشْتِرَاءِ التَّمْرِ بِالرُّطَبِ
it was narrated that Sa'd said:
"The Messenger of Allah was asked about (buying) fresh dates with dried dates, and he said to those who were around him: 'Will fresh dates decrease (in weight or volume) when they dry out?" they said Yes,' so he forbade that." (IT)
Reference (IT): Sunan an-Nasa'i 4545 (IT)
In-book reference (IT): Book 44, Hadith 97 (IT)
English translation (IT): Vol. 5, Book 44, Hadith 4549 (IT)