Hebrews 2:1

For this reason we should give heed more abundantly to the things we have heard, lest in any way we should slip away.

Proverbs 3:21

My son, let them not depart from thine eyes; keep sound wisdom and discretion:

Deuteronomy 4:9

Only take heed to thyself, and keep thy soul diligently, lest thou forget the things that thine eyes have seen (and lest they depart from thy heart all the days of thy life; but thou shalt make them known to thy sons and to thy sons' sons),

Deuteronomy 4:23

Take heed to yourselves lest ye forget the covenant of Jehovah your God, which he made with you, and make yourselves a graven image, the form of anything which Jehovah thy God hath forbidden thee.

Deuteronomy 32:46-47

he said unto them, Set your hearts unto all the words that I testify among you this day, which ye shall command your children to take heed to do, all the words of this law.

Joshua 23:11-12

Take great heed therefore unto your souls, that ye love Jehovah your God.

1 Chronicles 22:13

Then shalt thou prosper, if thou takest heed to perform the statutes and ordinances which Jehovah commanded Moses for Israel: be strong and courageous; fear not, neither be dismayed.

Psalm 119:9

BETH. Wherewithal shall a young man cleanse his path? by taking heed according to thy word.

Proverbs 2:1-6

My son, if thou receivest my words, and layest up my commandments with thee,

Proverbs 4:1-4

Hear, ye children, the instruction of a father, and attend to know intelligence;

Proverbs 4:20-22

My son, attend to my words; incline thine ear unto my sayings.

Proverbs 7:1-2

My son, keep my words, and lay up my commandments with thee.

Matthew 16:9

Do ye not yet understand nor remember the five loaves of the five thousand, and how many hand-baskets ye took up?

Mark 8:18

Having eyes, see ye not? and having ears, hear ye not? and do ye not remember?

Luke 8:15

But that in the good ground, these are they who in an honest and good heart, having heard the word keep it, and bring forth fruit with patience.

Luke 9:44

Do ye let these words sink into your ears. For the Son of man is about to be delivered into men's hands.

Hebrews 1:1-2

God having spoken in many parts and in many ways formerly to the fathers in the prophets,

Hebrews 2:2-4

For if the word which was spoken by angels was firm, and every transgression and disobedience received just retribution,

Hebrews 12:5

And ye have quite forgotten the exhortation which speaks to you as to sons: My son, despise not the chastening of the Lord, nor faint when reproved by him;

Hebrews 12:25-26

See that ye refuse not him that speaks. For if those did not escape who had refused him who uttered the oracles on earth, much more we who turn away from him who does so from heaven:

2 Peter 1:12-13

Wherefore I will be careful to put you always in mind of these things, although knowing them and established in the present truth.

2 Peter 1:15

but I will use diligence, that after my departure ye should have also, at any time, in your power to call to mind these things.

2 Peter 3:1

This, a second letter, beloved, I already write to you, in both which I stir up, in the way of putting you in remembrance, your pure mind,

Habakkuk 1:6

For behold, I raise up the Chaldeans, that bitter and impetuous nation, which marcheth through the breadth of the earth, to possess dwelling-places that are not theirs.

Habakkuk 2:16

Thou art filled with shame instead of glory; drink thou also, and let thy foreskin be uncovered: the cup of Jehovah's right hand shall be turned unto thee, and a shameful spewing shall be on thy glory.

Treasury of Scripture Knowledge

Summary

Therefore we ought to give the more earnest heed to the things which we have heard, lest at any time we should let them slip.

Let them slip

Bible References

Therefore

Hebrews 2:2
For if the word which was spoken by angels was firm, and every transgression and disobedience received just retribution,
Hebrews 1:1
God having spoken in many parts and in many ways formerly to the fathers in the prophets,
Hebrews 12:25
See that ye refuse not him that speaks. For if those did not escape who had refused him who uttered the oracles on earth, much more we who turn away from him who does so from heaven:

The more

Deuteronomy 4:9
Only take heed to thyself, and keep thy soul diligently, lest thou forget the things that thine eyes have seen (and lest they depart from thy heart all the days of thy life; but thou shalt make them known to thy sons and to thy sons' sons),
Deuteronomy 32:46
he said unto them, Set your hearts unto all the words that I testify among you this day, which ye shall command your children to take heed to do, all the words of this law.
Joshua 23:11
Take great heed therefore unto your souls, that ye love Jehovah your God.
1 Chronicles 22:13
Then shalt thou prosper, if thou takest heed to perform the statutes and ordinances which Jehovah commanded Moses for Israel: be strong and courageous; fear not, neither be dismayed.
Psalm 119:9
BETH. Wherewithal shall a young man cleanse his path? by taking heed according to thy word.
Proverbs 2:1
My son, if thou receivest my words, and layest up my commandments with thee,
Proverbs 3:21
My son, let them not depart from thine eyes; keep sound wisdom and discretion:
Proverbs 4:1
Hear, ye children, the instruction of a father, and attend to know intelligence;
Proverbs 7:1
My son, keep my words, and lay up my commandments with thee.
Luke 8:15
But that in the good ground, these are they who in an honest and good heart, having heard the word keep it, and bring forth fruit with patience.
Luke 9:44
Do ye let these words sink into your ears. For the Son of man is about to be delivered into men's hands.

We should

Hebrews 12:5
And ye have quite forgotten the exhortation which speaks to you as to sons: My son, despise not the chastening of the Lord, nor faint when reproved by him;
Matthew 16:9
Do ye not yet understand nor remember the five loaves of the five thousand, and how many hand-baskets ye took up?
Mark 8:18
Having eyes, see ye not? and having ears, hear ye not? and do ye not remember?
2 Peter 1:12
Wherefore I will be careful to put you always in mind of these things, although knowing them and established in the present truth.
2 Peter 3:1
This, a second letter, beloved, I already write to you, in both which I stir up, in the way of putting you in remembrance, your pure mind,

Let them slip

Habakkuk 1:6
For behold, I raise up the Chaldeans, that bitter and impetuous nation, which marcheth through the breadth of the earth, to possess dwelling-places that are not theirs.
Habakkuk 2:16
Thou art filled with shame instead of glory; drink thou also, and let thy foreskin be uncovered: the cup of Jehovah's right hand shall be turned unto thee, and a shameful spewing shall be on thy glory.

General references

Exodus 16:32
And Moses said, This is the thing which Jehovah has commanded: Fill an omer of it to be kept for your generations; that they may see the bread that I gave you to eat in the wilderness, when I brought you out of the land of Egypt.
Deuteronomy 6:8
And thou shalt bind them for a sign on thy hand, and they shall be for frontlets between thine eyes.
Deuteronomy 16:9
Seven weeks shalt thou count: from the beginning of putting the sickle into the corn shalt thou begin to count seven weeks.
Deuteronomy 32:46
he said unto them, Set your hearts unto all the words that I testify among you this day, which ye shall command your children to take heed to do, all the words of this law.