“forget not my law; but let thine heart keep my commandments”

My son, forget not my law; but let thine heart keep my commandments: 2 For length of days,and long life, and peace, shall they add to thee.
Proverbs 3.1-2

“write them upon the table of thine heart”

Let not mercy and truth forsake thee: bind them about thy neck; write them upon the table of thine heart
Proverbs 3.3

“written not with ink but by the Spirit of the living God”

“but on tablets of flesh, that is, of the heart.”

clearly you are an epistle of Christ, ministered by us, written not with ink but by the Spirit of the living God, not on tablets of stone but on tablets of flesh, that is, of the heart.
2 Corinthians 3.3

“My son, give attention to my words”

“Keep them in the midst of your heart”

My son, give attention to my words;
Incline your ear to my sayings.
21 Do not let them depart from your eyes;
Keep them in the midst of your heart;
Proverbs 4.20-21

“Keep your heart with all diligence,
For out of it spring the issues of life.”

Keep your heart with all diligence,
For out of it spring the issues of life.
Proverbs 4.23

“For the mouth speaks what the heart is full of.”

A good man brings good things out of the good stored up in his heart, and an evil man brings evil things out of the evil stored up in his heart. For the mouth speaks what the heart is full of.
Luke 6.45

“A man’s stomach shall be satisfied from the fruit of his mouth;
From the produce of his lips he shall be filled.”

A man’s stomach shall be satisfied from the fruit of his mouth;
From the produce of his lips he shall be filled.
Proverbs 18.20