Mishkat al-Masabih 2924
Suwaid b. Qais said:
Makhrafa al-‘Abdi and I imported some garments from Hajar* and brought them to Mecca. God’s Messenger came to us walking and after he had bargained with us for some trousers we sold them to him. God’s Messenger then said to a man there who was weighing out for pay, “Weigh out and give overweight.” 
*A name applied to the whole district of al-Bahrain.

Ahmad, Abu Dawud, Tirmidhi, Ibn Majah and Darimi transmitted it, Tirmidhi saying this is a hasan sahih tradition.
عَن سُوَيْد بن قيس قَالَ: جَلَبْتُ أَنَا وَمَخَرَفَةُ الْعَبْدِيُّ بَزًّا مِنْ هَجَرٍ فَأَتَيْنَا بِهِ مَكَّةَ فَجَاءَنَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَمْشِي فَسَاوَمَنَا بِسَرَاوِيلَ فَبِعْنَاهُ وَثمّ رجل يزن بِالْأَجْرِ فَقَالَ لَهُ رَسُول الله: «زِنْ وَأَرْجِحْ» . رَوَاهُ أَحْمَدُ وَأَبُو دَاوُدَ وَالتِّرْمِذِيُّ وَابْنُ مَاجَهْ وَالدَّارِمِيُّ وَقَالَ التِّرْمِذِيُّ: هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ