At the start of the prayer (after takbeer)
O Allah, separate me from my sins as You have separated the East from the West. O Allah, cleanse me ...
اللّهُـمَّ باعِـدْ بَيـني وَبَيْنَ خَطـايايَ كَما باعَدْتَ بَيْنَ المَشْرِقِ وَالمَغْرِبْ اللّهُـمَّ نَقِّنـي مِنْ خَطايايَ …
"O Allah, separate me from my sins as You have separated the East from the West. O Allah, cleanse me of my …"