Structurally, Psalm 128 has two sections: vv. 1–4 and vv. 5–6. The first 4 verses cohere as a result of the repetition (i.e., an inclusio) in v. 1 and v. 4, as shown below:
1 Blessed is everyone who fears the LORD, who walks in his ways!
2 You shall eat the fruit of the labor of your hands;
you shall be blessed, and it shall be well with you.
3 Your wife will be like a fruitful vine within your house;
your children will be like olive shoots around your table.
4 Behold, thus shall the man be blessed who fears the LORD. (ESV)
I did not highlight the term “blessed” in these two verses because we are dealing with two different words. The first (אַשְׁרֵי) is the same form used in Psalm 127:5 (“Blessed is the man …”) among other places in the Psalter (such as Pss. 1:1; 2:12). It is used here in Psalm 128:2, as well, in the phrase “you shall be blessed.” These verses imply a tangible happiness (or satisfaction) for the one who fears the Lord. Likewise, the psalmist describes the fear of the Lord tangibly as walking in the ways of Yhwh. Just as the one who fears the Lord—manifested by following his word—is blessed, so the reader is again invited to relate this to the opening two psalms. In Psalm 1, the one who mediates upon the teachings of the Lord is blessed; in Psalm 2, kings are exhorted to worship Yhwh “in fear” (v. 11), and blessing is found for those who take refuge in the Son. Moreover, the tangible evidences of this blessing in Psalm 128 (eating the fruit of the land as a result of work, a fruitful wife, prospering children) set this hope within the context of Genesis 1–3. These blessings show a virtual reversal of the curses of Genesis 3 within the context of the original creation blessing and mandate to “be fruitful and fill the land” (Gen 1:28).
The second term for blessing (יְבֹרַךְ) refers to blessing that is bestowed upon the one who fears the Lord. The presence of this term here prepares the reader for the second section of the psalm (vv. 5, 6), where such blessing is spoken over the individual. It thus links the physical blessings of vv. 2, 3 with the act of blessing done by Yhwh (v. 5, see below). This ensures that the source of this blessing is not missed.
4 Behold, thus shall the man be blessed who fears the LORD.
5 The LORD bless you from Zion!
May you see the prosperity of Jerusalem all the days of your life!
6 May you see your children’s children!
Peace be upon Israel! (ESV)
The promise of blessing upon the one who fears Yhwh in v. 4 has become the request for blessing upon the one over whom this blessing is spoken in v. 5. This request for blessing in v. 5 is echoed later in Psalm 134:3 verbatim.
Throughout the Songs of Ascents, there have been a number of connections with the Priestly Blessing of Numbers 6, and that trend continues in Psalm 128. Just as the priests were commanded to “bless” (using the latter term) the people of Israel, so the writer of Psalm 128 speaks with confidence of Yhwh’s blessing on those who fear Yhwh (v. 4) and also speaks a blessing upon the reader(s) (v. 5). As such, Psalm 128 acts as a rehearsal of the Priestly Blessing (in much the same way was Psalm 134 will also) but carefully places the origin of that blessing from Zion. The phrase, “peace upon Israel,” both enhances the connection to the Priestly Blessing and brings coherence within the Songs of Ascents as it echoes Psalm 125:5.
One of (if not the) central point of the psalm is to show that the blessing of one who fears Yhwh (vv. 1–4) manifests itself within the promise of a peaceful Zion/Jerusalem/Israel (vv. 5–6). As such, within the context of the Songs of Ascents and the Psalter, the blessing comes as part of the eschatological Messianic kingdom, which will continue to be described in the rest of the Songs of Ascents (see especially Psalm 132).