"This is what you were promised," meaning: the Garden, "for every one who returns (in repentance) and guards (His commands)." The awwab (one who returns) is the one who returns from his sin.
﴿هَذَا مَا توعدون﴾ يَعْنِي: الْجنَّة ﴿لِكُلِّ أَوَّابٍ حَفِيظٍ﴾ (ل ٣٣٦) الأواب: الرَّاجِع عَن ذَنبه