Truly God is good to Israel - Captives as they were, they still had many blessings from God; and they had promises of deliverance, which must be fulfilled in due time.

Such as are of a clean heart - Those who have a clean heart must have inward happiness: and, because they resemble God, they can never be forsaken by him.

Psalm 50:1 The mighty God, even the LORD, has spoken, and called the earth from the rising of the sun to the going down thereof.

Psalm 74:1 O God, why have you cast us off for ever? why does your anger smoke against the sheep of your pasture?

Psalm 83:1 Keep not you silence, O God: hold not your peace, and be not still, O God.

1 Chronicles 6:39 And his brother Asaph, who stood on his right hand, even Asaph the son of Berachiah, the son of Shimea,

1 Chronicles 15:17 So the Levites appointed Heman the son of Joel; and of his brothers, Asaph the son of Berechiah...

1 Chronicles 16:7,37 Then on that day David delivered first this psalm to thank the LORD into the hand of Asaph and his brothers...

1 Chronicles 25:1-6 Moreover David and the captains of the host separated to the service of the sons of Asaph, and of Heman, and of Jeduthun...

2 Chronicles 29:30 Moreover Hezekiah the king and the princes commanded the Levites to sing praise to the LORD with the words of David...

truly. or. yet

Psalm 2:6 Yet have I set my king on my holy hill of Zion.

Psalm 42:11 Why are you cast down, O my soul? and why are you disquieted within me? hope you in God: for I shall yet praise him...

God

Psalm 73:18-28 Surely you did set them in slippery places: you cast them down into destruction...

Psalm 84:11 For the LORD God is a sun and shield: the LORD will give grace and glory: no good thing will he withhold from them that walk uprightly.

Isaiah 63:7-9 I will mention the loving kindnesses of the LORD, and the praises of the LORD, according to all that the LORD has bestowed on us...

Luke 12:32 Fear not, little flock; for it is your Father's good pleasure to give you the kingdom.

to such

John 1:47 Jesus saw Nathanael coming to him, and said of him, Behold an Israelite indeed, in whom is no guile!

Romans 2:28,29 For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh...

Romans 4:16 Therefore it is of faith, that it might be by grace; to the end the promise might be sure to all the seed...

Romans 9:6,7 Not as though the word of God has taken none effect. For they are not all Israel, which are of Israel...

of a clean heart. Heb. clean of heart

Psalm 51:10 Create in me a clean heart, O God; and renew a right spirit within me.

Jeremiah 4:14 O Jerusalem, wash your heart from wickedness, that you may be saved. How long shall your vain thoughts lodge within you?

Matthew 5:8 Blessed are the pure in heart: for they shall see God.

Titus 3:5 Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration...

James 4:8 Draw near to God, and he will draw near to you. Cleanse your hands, you sinners; and purify your hearts, you double minded.

What is Meant by "Altogether Lovely"
Let us consider this excellent expression, and particularly reflect on what is contained in it, and you shall find this expression "altogether lovely." First, It excludes all unloveliness and disagreeableness from Jesus Christ. As a theologian long ago said, "There is nothing in him which is not loveable." The excellencies of Jesus Christ are perfectly exclusive of all their opposites; there is nothing of a contrary property or quality found in him to contaminate or devaluate his excellency. And …
John Flavel—Christ Altogether Lovely

The Great Gain of Godliness
'And Judah and Israel dwelt safely, every man under his vine and under his fig tree, from Dan even to Beer-sheba, all the days of Solomon. 26. And Solomon had forty thousand stalls of horses for his chariots, and twelve thousand horsemen. 27. And those officers provided victual for king Solomon, and for all that came unto king Solomon's table, every man in his month: they lacked nothing. 28. Barley also and straw for the horses and dromedaries brought they unto the place where the officers were, …
Alexander Maclaren—Expositions of Holy Scripture

Of Meditating on the Future Life.
1. The design of God in afflicting his people. 1. To accustom us to despise the present life. Our infatuated love of it. Afflictions employed as the cure. 2. To lead us to aspire to heaven. 2. Excessive love of the present life prevents us from duly aspiring to the other. Hence the disadvantages of prosperity. Blindness of the human judgment. Our philosophizing on the vanity of life only of momentary influence. The necessity of the cross. 3. The present life an evidence of the divine favour to his …
John Calvin—The Institutes of the Christian Religion