84:5 Blessed are those whose strength is in you, whose hearts are set on pilgrimage. The temple is the “strength” of those “who dwell in your house” (84:4). Kidner makes the attractive suggestion that the word “blessed” is used three ways: first, longingly (84:4), second, resolutely (84:5), and third, contentedly (84:12). Literally, the verse reads: “Blessed is the man whose strength is in you, (the) ways in their heart.” The personal pronoun “you” may mean either the Lord or the temple. Since the pronoun in verse 4 is clearly the Lord, it logically follows that in verse 5a it also means the Lord (“whose strength is in you” [the Lord]); but in verse 5b, since this half line focuses on the journey (“paths,” “roads”; cf. NET) the pronoun “their” at the end of the line (lit., “in their heart[s]”) seems to be pilgrims: “[its] ways are in their heart[s]” (NIV: “whose hearts are set on pilgrimage”). See “Teaching the Text.”
84:5 In verses 5–7 we switch back from the blessedness of those who are already in heaven to the lesser blessedness of those who are en route. Several things are mentioned about them. First of all, their strength is in the Lord, not in themselves. They are “strong in the Lord and in the power of His might” (Eph. 6:10). Then in their heart are the highways to Zion. The world is not their home. Though in it, they are not of it. Their heart is set on pilgrimage.
84:5 Blessed. See note Ps. 1:1.
whose strength is in you. Their vitality in life is found in God’s power, not in their own.
the highways. People living outside of Jerusalem made special trips to the temple to enjoy God’s presence in worship. The Songs of Ascents (120–134) were probably used during these journeys (120:title).
5. Blessed is the man whose strength is in thee. David again informs us, that the purpose for which he desired liberty of access to the sanctuary was, not merely to gratify his eyes with what was to be seen there, but to make progress in faith. To lean with the whole heart upon God, is to attain to no ordinary degree of advancement: and this cannot be attained by any man, unless all his pride is laid prostrate in the dust, and his heart truly humbled. In proposing to himself this way of seeking God, David’s object is to borrow from him by prayer the strength of which he feels himself to be destitute. The concluding clause of the verse, the ways are in their hearts, is by some interpreted as meaning, That those are happy who walk in the way which God has appointed; for nothing is more injurious to a man than to trust in his own understanding. It is not improperly said of the law, “This is the way, walk ye in it,” Isa. 30:21. Whenever then men turn aside, however little it may be, from the divine law, they go astray, and become entangled in perverse errors. But it is more appropriate to restrict the clause to the scope of the passage, and to understand it as implying, that those are happy whose highest ambition it is to have God as the guide of their life, and who therefore desire to draw near to him. God, as we have formerly observed, is not satisfied with mere outward ceremonies. What he desires is, to rule and keep in subjection to himself all whom he invites to his tabernacle. Whoever then has learned how great a blessedness it is to rely upon God, will put forth all the desires and faculties of his mind, that with all speed he may hasten to Him.
Ver. 5.—Blessed is the man whose strength is in thee. God is the “Strength” of all who trust in him. The psalmist seems to mean that mere dwelling in the house of God is not enough for blessedness. Trust in God—having God for one’s Strength—is also requisite (comp. ver. 12). In whose heart are the ways of them; literally, in whose heart are highways. The “highways” intended are probably those of holiness (comp. Prov. 16:17 and Isa. 35:8).
 MacDonald, W. (1995). Believer’s Bible Commentary: Old and New Testaments. (A. Farstad, Ed.) (pp. 677–678). Nashville: Thomas Nelson.
 Sproul, R. C. (Ed.). (2005). The Reformation Study Bible: English Standard Version (p. 811). Orlando, FL; Lake Mary, FL: Ligonier Ministries.