1 Chronicles 28:20

Overview - 1 Chronicles 28
David in a solemn assembly having declared God's favour to him, and promise to his son Solomon, exhorts them to fear God.
He encourages Solomon to build the temple.
11 He gives him patterns, gold and silver, etc.
Treasury of Scripture Knowledge

1 Chronicles 28:20  (King James Version)
And David said to Solomon his son, Be strong and of good courage, and do it: fear not, nor be dismayed: for the LORD God, even my God, will be with thee; he will not fail thee, nor forsake thee, until thou hast finished all the work for the service of the house of the LORD.

Be strong
10 ; 22:13 Deuteronomy 31:7 Deuteronomy 31:8 ; Joshua 1:6-9 ; 1 Corinthians 16:13

fear not
Psalms 27:1 Psalms 27:2 ; Isaiah 41:10 Isaiah 41:13 ; Romans 8:31

he will not fail thee
Joshua 1:5 ; Hebrews 13:5