Tafsir Ibn Kathir -> Surah Al-Hajj -> The Reward for avoiding Sin

Allah says: `This is what We have commanded you to do in the rituals (of Hajj), and this is the great reward that the person who does that will gain.'

﴿وَمَن يُعَظِّمْ حُرُمَـتِ اللَّهِ﴾

(whoever honors the sacred things of Allah,) means, whoever avoids disobeying Him and does not transgress that which is sacred, and regards committing sin as a very serious matter,

﴿فَهُوَ خَيْرٌ لَّهُ عِندَ رَبِّهِ﴾

(then that is better for him with his Lord.) means, he will attain much good and a great reward for doing that. Just as the one who does acts of obedience will earn a great reward, so too, the one who avoids sin will earn a great reward.