(11) Business Transactions
كتاب البيوع
(1c) Chapter: Earning, and Seeking what is Lawful - Section 3
(1) باب الكسب وطلب الحلال - الفصل الثالث
Mishkat al-Masabih 2781 
‘Abdallah b. Mas'ud reported God's Messenger as saying, “Trying to earn a lawful livelihood is an obligatory duty in addition to the duties which are obligatory.” Baihaqi transmitted it in Shu’ab al-iman.
عَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «طَلَبُ كَسْبِ الْحَلَالِ فَرِيضَةٌ بَعْدَ الْفَرِيضَةِ» . رَوَاهُ الْبَيْهَقِيُّ فِي شعب الْإِيمَان
 ضَعِيف  (الألباني)حكم :
Reference : Mishkat al-Masabih 2781
In-book reference : Book 11, Hadith 23