Messenger of Allah ﷺ said, "(The performance of) ʿUmra is an expiation for the sins committed (between it and the previous one). And the reward of Hajj Mabrur (the one accepted by Allah) is nothing except Paradise." (Using translation from Bukhārī 1773)  

قَالَ رَسُولُ اللهِ ﷺ «الْعُمْرَةُ إِلَى الْعُمْرَةِ كَفَّارَةٌ لِمَا بَيْنَهُمَا وَالْحَجُّ الْمَبْرُورُ لَيْسَ لَهُ جَزَاءٌ إِلَّا الْجَنَّةُ»  

"The Messenger of Allah said: 'Perform Hajj and 'Umrah consecutively; for they remove poverty and sin as the bellows removes impurity from iron.''' (Using translation from Nasāʾī 2630)  

قَالَ رَسُولُ اللهِ ﷺ «تَابِعُوا بَيْنَ الْحَجِّ وَالْعُمْرَةِ فَإِنَّهُمَا يَنْفِيَانِ الذُّنُوبَ كَمَا يَنْفِي الْكِيرُ خَبَثَ الْحَدِيدِ»