1 Chronicles 10:13

Thus died Saul, for his unfaithfulness wherewith he dealt unfaithfully against Yahweh, over the word of Yahweh, which he kept not, - and, also, in asking by necromancy when he desired to enquire;

Leviticus 19:31

Do not turn unto mediums, Nor, for oracles, make search, To render yourselves unclean with them, I - Yahweh, am your God.

Leviticus 20:6

The person also that turneth unto mediums and unto oracles, in going unchastely after them, then will I set my face against that person, and will cut him off out of the midst of his people.

1 Samuel 15:23

For, as the sin of divination, is, rebelliousness, - and, as transgression with household gods, is, stubbornness, - Because thou hast rejected the word of Yahweh, therefore hath he rejected thee from being king.

Deuteronomy 18:10-14

There shall not be found in thy midst - One who causeth his son or his daughter to pass through fire, - Or who useth divination, hidden arts or enchantments Or who muttereth incantations;

Isaiah 8:19

But, when they say unto you - Seek ye unto the necromancers and unto the wizards, who chirp, and who mutter, Should not u people seek, unto its God? In behalf of the living, should it seek unto the dead?

Exodus 22:18

A sorceress, shalt thou not suffer to live.

1 Samuel 13:13-14

And Samuel said unto Saul - Thou hast shewn thyself foolish, - thou hast not kept the commandment of Yahweh thy God, which he commanded thee, for, now, would Yahweh have established thy kingdom unto Israel until times age-abiding;

1 Samuel 15:2

Thus, saith Yahweh of hosts, I have well considered what Amalek did unto Israel - how he lay in wait for him in the way, when he came up out of Egypt.

1 Samuel 28:7-20

Then said Saul unto his servants - Seek me out a woman that owneth a familiar spirit, that I may even go unto her, and enquire of her. And his servants said unto him, Lo! there is a woman that owneth a familiar spirit in En-dor.

2 Kings 21:6

and caused his son to pass through the fire, and practiced hidden arts and used divination, and dealt with a familiar spirit and wizards, - he exceeded in doing the thing that was wicked in the eyes of Yahweh, provoking him to anger;

Acts 8:9-11

But, a certain man named Simon, was already in the city, practising magical arts, and astonishing the nation of Samaria, - saying that himself was someone great:

Acts 16:16-18

And it came to pass, as we were on our way unto the place of prayer, a certain damsel, having a spirit of Python, met us, - who, indeed, much gain, was presenting unto her masters, by divining.

Treasury of Scripture Knowledge

Summary

So Saul died for his transgression which he committed against the LORD, even against the word of the LORD, which he kept not, and also for asking counsel of one that had a familiar spirit, to inquire of it;

For asking

General references

Bible References

Even against

1 Samuel 13:13
And Samuel said unto Saul - Thou hast shewn thyself foolish, - thou hast not kept the commandment of Yahweh thy God, which he commanded thee, for, now, would Yahweh have established thy kingdom unto Israel until times age-abiding;
1 Samuel 15:2
Thus, saith Yahweh of hosts, I have well considered what Amalek did unto Israel - how he lay in wait for him in the way, when he came up out of Egypt.

For asking

1 Samuel 28:7
Then said Saul unto his servants - Seek me out a woman that owneth a familiar spirit, that I may even go unto her, and enquire of her. And his servants said unto him, Lo! there is a woman that owneth a familiar spirit in En-dor.

A familiar

Exodus 22:18
A sorceress, shalt thou not suffer to live.
Leviticus 19:31
Do not turn unto mediums, Nor, for oracles, make search, To render yourselves unclean with them, I - Yahweh, am your God.
Leviticus 20:6
The person also that turneth unto mediums and unto oracles, in going unchastely after them, then will I set my face against that person, and will cut him off out of the midst of his people.
Deuteronomy 18:10
There shall not be found in thy midst - One who causeth his son or his daughter to pass through fire, - Or who useth divination, hidden arts or enchantments Or who muttereth incantations;
2 Kings 21:6
and caused his son to pass through the fire, and practiced hidden arts and used divination, and dealt with a familiar spirit and wizards, - he exceeded in doing the thing that was wicked in the eyes of Yahweh, provoking him to anger;
Isaiah 8:19
But, when they say unto you - Seek ye unto the necromancers and unto the wizards, who chirp, and who mutter, Should not u people seek, unto its God? In behalf of the living, should it seek unto the dead?
Acts 8:9
But, a certain man named Simon, was already in the city, practising magical arts, and astonishing the nation of Samaria, - saying that himself was someone great:
Acts 16:16
And it came to pass, as we were on our way unto the place of prayer, a certain damsel, having a spirit of Python, met us, - who, indeed, much gain, was presenting unto her masters, by divining.

General references

Leviticus 19:31
Do not turn unto mediums, Nor, for oracles, make search, To render yourselves unclean with them, I - Yahweh, am your God.