When entering the Market
Recite:
لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ ، لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ يُحْيِي وَيُمِيتُ
وَهُوَ حَيٌّ لَا يَمُوتُ بِيَدِهِ الْخَيْرُ وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٍ
"There is none worthy of worship besides Allah. He is all by
Himself. He has no partner. His is the Kingdom, to Him is
all praise. He gives and takes life. He is all by Himself. He
will not die. In His hands is all good and He has control
(power) over all things".
It is stated in the hadith that if a person reads the above dua
in the market place, Allah writes ten lakh rewards for him
and forgives ten lakh sins and raises his status by ten lakh
and a house is prepared for him in Jannah.
N.B. one lakh = 100,000 (Tirmidhi, Ibn Maja)
When buying or selling at the Market
Recite:
بِسْمِ اللَّهِ إِنِّي أَسْأَلُكَ خَيْرُ هَذِهِ السُّوقِ وَخَيْرُ مَا فِيهَا وَأَعُوذُ بِكَ مِنْ
شَرِّهَا وَشَرِّ مَا فِيهَا اللَّهُمَّ إِنِّي أَعُوذُ بِكَ أَنْ أُصِيبَ فِيهَا يَمِينَاً فَاجِرَةً
أَوْ صَفْقَةً خَاسِرَةً
"I entered in the name of Allah, I seek refuge in You (Allah)
for the good in the bazaar and for the good of what is in it
(the bazaar). O Allah, I seek refuge in you from false oaths
and deception in transaction".
(Hisnul Hasin)
Additionally:
On returning from the bazaar, recite any ten ayats of the
Qur'an (i.e. from anywhere) (Hisnul Hasin from Tabarani)