When entering a marketplace, one should say: 'La ilaha illallahu wahdahu la sharika lah, lahul-mulku wa lahul-hamdu, yuhyi wa yumitu wa Huwa hayyun la yamut, biyadihil-khayru wa Huwa 'ala kulli shay'in qadir.' This earns immense rewards for remembering Allah where most people are heedless.
لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ، لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ، يُحْيِي وَيُمِيتُ وَهُوَ حَيٌّ لَا يَمُوتُ، بِيَدِهِ الْخَيْرُ وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ
La ilaha illallahu wahdahu la sharika lah, lahul-mulku wa lahul-hamdu, yuhyi wa yumitu wa Huwa hayyun la yamut, biyadihil-khayru wa Huwa 'ala kulli shay'in qadir.
Meaning: There is no god but Allah, alone, without partner. To Him belongs dominion and to Him belongs praise. He gives life and causes death, and He is Living and does not die. In His hand is all goodness, and He is over all things capable.
Source: Sunan al-Tirmidhi #3428The immense reward of doa ini comes from remembering Allah in a place where most people are heedless and absorbed in worldly pursuits. Nabi indicated that whoever remembers Allah in the marketplace earns a million good deeds, has a million bad deeds erased, and is raised a million degrees. Scholars explain that the reward is multiplied because dhikr is rare in such settings.
لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ، لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ، يُحْيِي وَيُمِيتُ وَهُوَ حَيٌّ لَا يَمُوتُ، بِيَدِهِ الْخَيْرُ وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ
The Prophet (peace be upon him) said: 'Whoever enters the marketplace and says: La ilaha illallahu wahdahu la sharika lah... Allah will record for him a million good deeds, erase from him a million bad deeds, and raise him a million degrees.'