Let your conversation - Your “conduct” - for so the word “conversation” is used in the Scriptures; notes, Philippians 1:27.
Be without covetousness - Ephesians 5:3 note; Colossians 3:5 note.
And be content with such things as ye have - see the Philippians 4:11-12 notes; Matthew 6:25-34 notes. The particular reason here given for contentment is, that God has promised never to leave his people. Compare with this the beautiful argument of the Saviour in Matthew 6:25 ff.
For he hath said - That is, God has said.
I will never leave thee nor forsake thee - see Deuteronomy 31:6; Joshua 1:5; 1 Chronicles 28:20. Substantially the same expression is found in each of those places, and all of them contain the principle on which the apostle here relies, that God will not forsake his people.