Sunan an-Nasa'i, Hadith 4499 ⓘ
It was narrated that Ibn 'Umar said: "The Messenger of Allah forbade meeting traders on the way, until one enters the market with them?" Abu Usamah acknowledged it and said: Yes.
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ قُلْتُ لأَبِي أُسَامَةَ أَحَدَّثَكُمْ عُبَيْدُ اللَّهِ عَنْ نَافِعٍ عَنِ ابْنِ عُمَرَ قَالَ نَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم عَنْ تَلَقِّي الْجَلَبِ حَتَّى يَدْخُلَ بِهَا السُّوقَ فَأَقَرَّ بِهِ أَبُو أُسَامَةَ وَقَالَ نَعَمْ .
also referenced under: Book 44, Hadith 51 (In-Book) & Volume 5, Book 44, Hadith 4503 (DarusSalam)