Da'as Tevunos - Section 24

Said the Intellect - This completeness is clear from written sources and logical conclusions; and this is, that man should cleave to His holiness may he be blessed, and he will comprehend his glory without any detraction, separation or obstruction.

If you wish, [learn it from the] text (Isaiah 58:14), "Then shall you enjoy with HaShem..."; (Psalms 140:14), "...the upright shall dwell in your presence" (Psalms 16:11), "...experiencing joy is your presence..." etc, and very many others like these, are these not in all the corners of the words of the prophets and writings revealed to all the nations, seek from the texts of HaShem and read them. And in the words of our Rabbis may their memory be for a blessing (Brachos 17a), "The world to come has neither eating nor drinking...rather the righteous sit and their crowns are upon their heads, and they benefit in the splendor of HaShem's presence".

Or if you prefer to say it from a logical conclusion, the soul is a part of the Lord above, behold isn't its desire certainly to return and cleave to its source and to grasp it, as is the nature of everything of heavenly source to desire it return to the heights [of heaven], and it does not achieve its rest until it achieves this.

But what is this cleaving, and what is this achievement - we don't have the capacity to understand it as we exist within the state of deficiencies. But from this we discern our deficiencies, because like we knew that completeness is this cleaving, similarly we know that the deficiencies are all distancing from this, and that which obstructs and lays between us and Him may his name be blessed, for because of this it is impossible to cleave to him as it is possible to cleave to him after the obstruction is removed, and this is the deficiency which we need to try to remove, and to acquire the completeness that we mentioned. And indeed here we need a very fundamental introduction: